The shivaratri vrata (Why observed ?) is observed especially in the night of Krishna paksha chaturdashi of month kumba (mid Feb - mid Mar)  (Sivaratri dates for the current year). The complete night of shivaratri is spent in the worship of the Lord. In the four quarters (yAmas - 3 hours) of the night special prayers are done. The Puja procedure given here is short, but the chanting of shrI rudram or other stotras or the Panchakshara could be done throughout the night.

॥ śivarātri vrataṃ ॥

Perform Ganapati Puja praying for no hurdles to the pUja. 

śuklāmbaradharaṃ viṣṇuṃ śaśivarṇaṃ caturbhujam ।
prasannavadanaṃ dhyāyet sarvavighnopaśāntaye ॥

Do the sankalpa as prescribed below: 

mamopātta samasta durita kṣayadvāra śrī parameśvara prītyarttam
śubhe śobhane muhūrte ādyabrahmaṇaḥ dvitīyaparārdhe
śveta varāhakalpe vaivasvata manvam̐tare kaliyuge
prathamapāde jaṃbū dvīpe bhāratavarṣe bharatakhaṇḍe
asmin vartamāne vyavahārika - nāmena saṃvatsare
uttarāyane śiśira ṛtau kumba māse
kṛṣṇa pakṣe caturdhaśyām subhatitau - vāsara yuktāyām
śubhanakṣatra śubhayoga śubhakaraṇa evaṃguṇa viśeṣaṇa viśiṣṭāyāṃ
- śubhatithau śivarātri puṇyakāle śrī parameśvara prītyarthaṃ 
mama kṣemasthairya
vijayāyurārogyaiśvaryāpi vṛddhyarthaṃ dharmārtha
kāmamokṣa caturvidha phalapuruṣārtha siddhyarthaṃ
iṣṭa kāmyārtha siddhyarthaṃ mama samasta duritopa
śāntyarthaṃ samasta maṅgal̤a vāptyarthaṃ śrī sāmba sadāśiva
prasādena sakuṭumbasya jñāna vairāgya mokṣa prāptyarttam
varṣe varṣe prayukta śivarātri puṇyakāle samba parameśva pūjām kariṣye ॥

• Now do the kalasa pUja.
• Meditate on Lord sAmba parameshvara with this shloka:

candra kŏṭhi pratīkāśaṃ trinetraṃ candra bhūṣaṇam ।
āpiṅgal̤a jaṭājūṭaṃ ratna maul̤i virājitam ॥

nīlagrīvaṃ utārāṅgaṃ tārahāropa śobhitam ।
varadābhaya hastañca hariṇañca paraśvatam ॥

tatānaṃ nāga valayaṃ keyūrāṅgata mudrakam ।
vyāghra carma parītānaṃ ratna siṃhāsana sthitam ॥

āgacca devadeveśa martyaloka hiteccayā ।
pūjayāmi vidānena prasannaḥ sumukho bhava ॥

umā maheśvaraṃ dyāyāmi । āvāhayāmi ॥

• Do the prANa pratiShTA of Lord Shiva and perforM a simple pUjA with dhUpadIpaM and fruit offering

pādāsanaṃ kuru prājña nirmalaṃ svarṇa nirmitam ।
bhūṣitaṃ vivitaiḥ ratnaiḥ kuru tvaṃ pādukāsanam ॥

umā maheśvarāya namaḥ । ratnāsanaṃ samarpayāmi ॥

gaṅgādi sarva tīrthebhyaḥ mayā prārttanayāhṛtam ।
toyam ĕtat sukasparśam pādyārtham pradigṛhyatām ॥

umā maheśvarāya namaḥ । pādyaṃ samarpayāmi ॥

gandhodakena puṣpeṇa candanena sugandhinā ।
arghyaṃ kṛhāṇa deveśa bhaktiṃ me hyacalāṃ kuru ॥

umā maheśvarāya namaḥ । arghyaṃ samarpayāmi ॥

karpūrośīra surabhi śītal̤aṃ vimalaṃ jalam ।
gaṅgāyāstu samānītaṃ gṛhāṇācamaṇīyakam ॥

umā maheśvarāya namaḥ । ācamanīyaṃ samarpayāmi ॥

rasosi rasya vargeṣu suka rūposi śaṅkara ।
madhuparkaṃ jagannātha dāsye tubhyaṃ maheśvara ॥

umā maheśvarāya namaḥ । madhuparkaṃ samarpayāmi ॥

payodadhi kṛtañcaiva madhuśarkarayā samam ।
pañcāmṛtena snapanaṃ kāraye tvāṃ jagatpate ॥

umā maheśvarāya namaḥ । pañcāmṛta snānaṃ samarpayāmi ॥

mandhākiniyāḥ samānītaṃ hemāṃboruha vāsitam ।
snānāya te mayā bhaktyā nīraṃ svīkṛyatāṃ vibho ॥

umā maheśvarāya namaḥ । śuddodaka snānam samarpayāmi । 
snānānantaraṃ ācamanīyaṃ samarpayāmi ॥

vastraṃ sūkṣmaṃ tukūleca devānāmapi durlabham ।
gṛhāṇa tvam umākānta prasanno bhava sarvatā ॥

umā maheśvarāya namaḥ । vastraṃ samarpayāmi ॥

yajñopavītaṃ sahajaṃ brahmaṇā nirmitaṃ purā ।
āyuṣyaṃ bhava varcasyaṃ upavītaṃ gṛhāṇa bho ॥

umā maheśvarāya namaḥ । yajñopavītaṃ samarpayāmi ॥

śrīkaṇṭhaṃ candanaṃ divyaṃ gandhāḍhyaṃ sumanoharam ।
vilepanaṃ suraśreṣṭa matdattam prati gṛhyatām ॥

umā maheśvarāya namaḥ । gandhaṃ samarpayāmi ॥

akṣadān candra varṇāpān śāleyān sadilān śubhān ।
alañkārārthamānīdān dhārayasya mahāprabho ॥

umā maheśvarāya namaḥ । akṣadān samarpayāmi ॥

mālyātīni sugandhīni maladyātīni vai prabho ।
mayāhṛdāni puṣpāṇi pūjārthaṃ tava śañkara ॥

umā maheśvarāya namaḥ । puṣpamālāṃ samarpayāmi ॥

॥ aṅga pūjā ॥

śivāya namaḥ । pādau pūjayāmi ।
śarvāya namaḥ ।  kulpau pūjayāmi ।
rudrāya namaḥ । jānunī pūjayāmi ।
īśānāya namaḥ ।  jaṅghe pūjayāmi ।
paramātmane namaḥ ।  ūrū pūjayāmi ।
harāya namaḥ ।  jaghanaṃ pūjayāmi ।
īśvarāya namaḥ । guhyaṃ pūjayāmi ।
svarṇa retase namaḥ ।  kaṭiṃ pūjayāmi ।
maheśvarāya namaḥ । nābhiṃ pūjayāmi ।
parameśvarāya namaḥ । udaraṃ pūjayāmi ।
sphaṭikābharaṇāya namaḥ ।  vakṣasthalaṃ pūjayāmi ।
tripurahantre namaḥ ।  bhāhūn pūjayāmi ।
sarvāstra dhāriṇe namaḥ ।  hastān pūjayāmi ।
nīlakaṇṭhāya namaḥ । kaṇṭhaṃ pūjayāmi ।
vācaspataye namaḥ । mukhaṃ pūjayāmi ।
tryambakāya namaḥ । netrāṇi pūjayāmi ।
phāla candrāya namaḥ ।  lalāṭaṃ pūjayāmi ।
gaṅgādharāya namaḥ ।  jaṭāmaṇḍalaṃ pūjayāmi ।
sadāśivāya namaḥ ।  śiraḥ pūjayāmi ।
sarveśvarāya namaḥ । sarvāṇyaṅgāni pūjayāmi ।

• Perform the Shiva Ashtottara sata or sahasra namavali Puja.

oṃ śivāya namaḥ
oṃ maheśvarāya namaḥ
oṃ śaṃbhave namaḥ
oṃ pinākine namaḥ
oṃ śaśiśekharāya namaḥ
oṃ vāmadevāya namaḥ
oṃ virūpākṣāya namaḥ
oṃ kapardine namaḥ
oṃ nīlalohitāya namaḥ
oṃ śaṅkarāya namaḥ
oṃ śūlapāṇaye namaḥ
oṃ khaṭvāṃgine namaḥ
oṃ viṣṇuvallabhāya namaḥ
oṃ śipiviṣṭāya namaḥ
oṃ aṃbikānāthāya namaḥ
oṃ śrīkaṇṭhāya namaḥ
oṃ bhaktavatsalāya namaḥ
oṃ bhavāya namaḥ
oṃ śarvāya namaḥ
oṃ trilokeśāya namaḥ
oṃ śitikaṇṭhāya namaḥ
oṃ śivāpriyāya namaḥ
oṃ ugrāya namaḥ
oṃ kapāline namaḥ
oṃ kāmāraye namaḥ
oṃ andhakāsura sūdanāya namaḥ
oṃ gaṅgādharāya namaḥ
oṃ lalāṭākṣāya namaḥ
oṃ kālakālāya namaḥ
oṃ kṛpānidhaye namaḥ
oṃ bhīmāya namaḥ
oṃ paraśuhastāya namaḥ
oṃ mṛgapāṇaye namaḥ
oṃ jaṭādharāya namaḥ
oṃ kailāsavāsine namaḥ
oṃ kavacine namaḥ
oṃ kaṭhorāya namaḥ
oṃ tripurāntakāya namaḥ
oṃ vṛṣāṃkāya namaḥ
oṃ vṛṣabhārūḍhāya namaḥ
oṃ bhasmoddhūlita vigrahāya namaḥ
oṃ sāmapriyāya namaḥ
oṃ svaramayāya namaḥ
oṃ trayīmūrtaye namaḥ
oṃ anīśvarāya namaḥ
oṃ sarvajñāya namaḥ
oṃ paramātmane namaḥ
oṃ somasūryāgnilocanāya namaḥ
oṃ haviṣe namaḥ
oṃ yajñamayāya namaḥ
oṃ somāya namaḥ
oṃ paṃcavaktrāya namaḥ
oṃ sadāśivāya namaḥ
oṃ viśveśvarāya namaḥ
oṃ vīrabhadrāya namaḥ
oṃ gaṇanāthāya namaḥ
oṃ prajāpataye namaḥ
oṃ hiraṇyaretase namaḥ
oṃ durdharṣāya namaḥ
oṃ girīśāya namaḥ
oṃ giriśāya namaḥ
oṃ anaghāya namaḥ
oṃ bhujaṅgabhūṣaṇāya namaḥ
oṃ bhargāya namaḥ
oṃ giridhanvane namaḥ
oṃ giripriyāya namaḥ
oṃ kṛttivāsase namaḥ
oṃ purārātaye namaḥ
oṃ bhagavate namaḥ
oṃ pramathādhipāya namaḥ
oṃ mṛtyuṃjayāya namaḥ
oṃ sūkṣmatanave namaḥ
oṃ jagadvyāpine namaḥ
oṃ jagadgurave namaḥ
oṃ vyomakeśāya namaḥ
oṃ mahāsenajanakāya namaḥ
oṃ cāruvikramāya namaḥ
oṃ rudrāya namaḥ
oṃ bhūtapataye namaḥ
oṃ sthāṇave namaḥ
oṃ ahirbudhnyāya namaḥ
oṃ digaṃbarāya namaḥ
oṃ aṣṭamūrtaye namaḥ
oṃ anekātmane namaḥ
oṃ sātvikāya namaḥ
oṃ śuddavigrahāya namaḥ
oṃ śāśvatāya namaḥ
oṃ khaṇḍaparaśave namaḥ
oṃ ajāya namaḥ
oṃ pāśavimocakāya namaḥ
oṃ mṛḍāya namaḥ
oṃ paśupataye namaḥ
oṃ devāya namaḥ
oṃ mahādevāya namaḥ
oṃ avyayāya namaḥ
oṃ haraye namaḥ
oṃ bhaganetrabhide namaḥ
oṃ avyaktāya namaḥ
oṃ dakṣādhvaraharāya namaḥ
oṃ harāya namaḥ
oṃ pūṣadantabhide namaḥ
oṃ avyagrāya namaḥ
oṃ sahasrākṣāya namaḥ
oṃ sahasrapade namaḥ
oṃ apavargapradāya namaḥ
oṃ anantāya namaḥ
oṃ tārakāya namaḥ
oṃ parameśvarāya namaḥ

sāmba parameśvarāya namaḥ । nānāvita parimal̤apatra
puṣpāṇi samarpayāmi ॥

vanaspatirasodbhūtaḥ gandhāḍhyaśca manoharaḥ ।
āgreyaḥ sarvadevānāṃ dhūpoyaṃ pratigṛhyatām ॥

umā maheśvarāya namaḥ । dhūpaṃ āgrāpayāmi ॥

sājyaṃ trivartti samyuktaṃ vahninā yojitaṃ mayā ।
dīpaṃ gṛhāṇa deveśa trailokya timirāpaham ॥

umā maheśvarāya namaḥ । dīpaṃ darśayāmi ॥

naivedyaṃ gṛhyatāṃ deva bhaktiṃ me hyacalāṃ kuru ।
śivepsitaṃ varaṃ dehi paratra ca parāṃ gatim ॥

umā maheśvarāya namaḥ । mahānaivedyaṃ samarpayāmi ॥

oṃ bhūrbhuvassuvaḥ tatsaviturvareṇyaṃ bhargo devasya 
dhīmahi diyo yo naḥ pracodayāt ।
oṃ deva savitaḥ prasūva satyaṃ tvarthena pariśiñcāmi ।
amṛtopastaraṇamasi । 
oṃ prāṇayasvāhā । oṃ apānāyasvāhā । oṃ vyānāya svāhā ।
oṃ udānāya svāhā । oṃ samānāya svāhā ।
oṃ brahmaṇe svāhā । brahmaṇi ma ātmā amṛtatvāya । 
amṛtābhitānamasi ॥

naivedyānantaraṃ ācamanīyaṃ samarpayāmi ।

pūgīphala samāyuktaṃ nāgavallī dal̤air yutam ।
karpūra cūrṇa saṃyuktaṃ tāṃbūlaṃ pratigṛhyatām ॥

umā maheśvarāya namaḥ । karpūra tāṃbūlaṃ samarpayāmi ॥

cakṣurtaṃ sarvalokānāṃ timirasya nivāraṇam ।
ārdigyaṃ kalpitaṃ bhaktyā gṛhāṇa parameśvara ॥

umā maheśvarāya namaḥ । karpūra nīrāñjanaṃ samarpayāmi । 
ācamanīyaṃ samarpayāmi ॥

yānikānica pāpāni janmāntara kṛtāni ca ।
tāni tāni vinaśyanti pradakṣiṇa pate pate ॥

umā maheśvarāya namaḥ । pradakṣiṇaṃ samarpayāmi ॥

puṣpāñjaliṃ pradāsyāmi gṛhāṇa karuṇānide ।
nīlakaṇṭha virūpākṣa vāmārda girija prabho ॥

umā maheśvarāya namaḥ । puṣpāñjaliṃ samarpayāmi । 
mantrapuṣpaṃ svarṇapuṣpaṃ samarpayāmi ॥

mantrahīnaṃ kriyāhīnaṃ bhaktihīnaṃ sureśvara ।
yatpūjitaṃ mayā deva paripūrṇam tatastu te ॥

vande śambhumumāpatiṃ suraguruṃ vande jagatkāraṇam 
vande pannagabhūṣaṇaṃ mṛgadharaṃ vande paśūṇām patim ।
vande sūrya śaśāṃkavahni nayanaṃ vande mukunda priyam 
vande bhakta janāśrayañca varadaṃ vande śivaṃ śaṅkaram ॥

namaḥśivābhyāṃ nava yauvanābhyāṃ 
parasparāśliṣṭa vapur dharābhyām ।
nagendra kanyā vṛṣa ketanābhyāṃ
namo namaḥśaṅkara pārvatībhyām ॥

॥ arghyam ॥

śuklāmbaradharaṃ viśḥṇuṃ śaśivarṇaṃ caturbhujaṃ ।
prasanna vadanaṃ dyāyet sarvavignopaśāntaye ॥

mamopātta samasta durita kṣayadvāra śrī parameśvara
prītyarttaṃ ।
mayācarita śivarātri vradapūjānte kṣīrārghya pradānaṃ 
upāyadānañca kariṣye ॥

namo viśvasvarūpāya viśvasṛṣṭyādi kāraka ।
gaṅgādhara namastubhyaṃ gṛhāṇārghyaṃ mayārpitam ॥

umā maheśvarāya namaḥ । idamarghyaṃ idamarghyaṃ idamarghyaṃ ॥

namaḥśivāya śāntāya sarvapāpaharāyaca ।
śivarātrau mayā dattam gṛhāṇārghyaṃ prasīta me ॥

umā maheśvarāya namaḥ । idamarghyaṃ idamarghyaṃ idamarghyaṃ ॥

duḥkha dāridrya pāpaiśca dagtohaṃ pārvatīpate ।
māṃ tvaṃ pāhi ,ahābhāho gṛhaṇārghyaṃ namostu te ॥

umā maheśvarāya namaḥ । idamarghyaṃ idamarghyaṃ idamarghyaṃ ॥

śivāya śivarūpāya bhaktānāṃ śivadāyaka ।
idamarghyaṃ pradāsyāmi prasanno bhava sarvatā ॥

umā maheśvarāya namaḥ । idamarghyaṃ idamarghyaṃ idamarghyaṃ ॥

aṃbikāyai namastubhyaṃ namaste devi pārvati ।
ambike varade devi gṛhṇīdārghyaṃ prasīda me ॥

pārvatyai namaḥ । idamarghyaṃ idamarghyaṃ idamarghyaṃ ॥

subraḥmaṇya mahābhaga kārtikeya sureśvara ।
idamarghyaṃ pradāsyāmi suprīto varado bhava ॥

subrahmaṇyāya namaḥ । idamarghyaṃ idamarghyaṃ idamarghyaṃ ॥

caṇḍikeśāya namaḥ । idamarghyaṃ idamarghyaṃ idamarghyaṃ ॥

anena arghya pradānena bhagavān sarvadevātmakaḥ saparivāra 
sāmba parameśvaraḥ prīyatām ॥

॥ upāyana dānam ॥

sāmbaśiva svarūpasya brāhmaṇasya itamāsanaṃ । amīte gandhāḥ ॥

• Give Tambula, Dakshina etc with the following mantra

hiraṇyagarbha garbhastaṃ hemabījaṃ vibhāvasoḥ ।
anantapuṇya phalataṃ ataḥ śāntiṃ prayacca me ॥

idamupāyanaṃ sadakṣiṇākaṃ satāṃbūlaṃ sāṃbaśivaprītiṃ kāmamānaḥ 
tubhyamahaṃ sampratate na mama ॥

oṃ samasta lokāḥ sukhino bhavantu ॥

। oṃ tatsat brahmārpaṇamastu ।