The term Shiva means auspicious. The God Shiva is all-auspiciousness. The mantra namaH Shivaya, used to offer salutations to Shiva, is an effective prayer to propitiate Shiva.
This pa.nchAkshara (five syllabled) mantra Namah Shivaya is sometimes called the mUla mantra or basic mantra of Shiva. Each of the five syllables, na, ma, shi, vA, and ya, is held to be so sacred that it represents Shiva even by itself. The following is the ShivapanchAkshara stotra composed by Adi SankarAchArya. One may worship the Shiva linga by reciting this stotra and offering bilva leaves. nAgendrahArAya trilochanAya bhasmAN^garAgAya maheshvarAya | nityAya shuddhAya digambarAya tasmai nakArAya namaH shivAya || 1|| Salutations to Shiva, who wears the King of snakes as a garland, the Three-eyed God, whose body is smeared with ashes, the great Lord, the eternal and pure One, who wears the directions as His garment, and who is represented by the mandAkini\-salilachandana\-charchitAya nandIshvara\-pramathanAtha\- maheshvarAya | mandArapushhpa\-bahupushhpa\-supUjitAya tasmai makArAya namaH shivAya || 2|| I bow to Shiva, who has been worshipped with water from the gangA (mandAkini) and annointed with sandalwood paste, the Lord of nandI, the Lord of the host of goblins and ghosts, the great Lord, who is worshiped with mandAra and many other kinds of flowers, and who is represented by the shivAya gaurIvadanAbja\-vR^inda\- sUryAya dakshAdhvaranAshakAya | shrInIlakaNThAya vR^ishhadhvajAya tasmai shikArAya namaH shivAya || 3|| Salutations to Shiva, who is all-auspiciousness, Who is the sun that causes the lotus face of GaurI (PArvatI) to blossom, Who is the destroyer of the Yajna of daksha, whose throat is blue (nIlakaNTha), whose flag bears the emblem of the bull, and who is represented by the syllable {\rm “}shi.{\rm ”} vasishhTha\-kumbhodbhava\-gautamAryamunIndra\-devArchitashekharAya | chandrArka\-vaishvAnaralochanAya tasmai vakArAya namaH shivAya || 4|| VasishhTha, agastya, Gautama, and other venerable sages, and Indra and other Gods have worshipped the head of (Shiva’s linga). I bow to that Shiva whose three eyes are the moon, sun and fire, and who is represented by the syllable yakshasvarUpAya jaTAdharAya pinAkahastAya sanAtanAya | divyAya devAya digambarAya tasmai yakArAya namaH shivAya || 5|| Salutations to Shiva, who bears the form of a Yaksha, who has matted hair on His head, Who bears the pinAka bow in His hand, the Primeval Lord, the brilliant God, who is digambara (naked), and who is represented by the syllable pa.nchAksharamidaM puNyaM yaH paThechchhivasannidhau | shivalokamavApnoti shivena saha modate || Anyone who recites this sacred five-syllabled mantra, (namaH shivAya) near the Shiva (linga), attains the abode of Shiva and rejoices there with Shiva. .. iti shriimachchha.nkaraachaaryavirachita shivapaJNchaakshara stotraM samaaptaM..