Aṣṭamūrtī - The Eight Forms of Shiva and their Worship

ॐ नमः शिवाय - ঔং নমঃ শিবায় - auṁ namaḥ śivāya

śiva aṣṭamūrtī and pūjā : शिव अष्टमूर्ती एवं पूजा : শিব অষ্টমূর্তী এবং পূজা

Introduction
There are eight forms of shiva which preside over eight domains:
sharva - earth
bhava - water
rudra  - fire
ugra - wind
bhIma - sky
pashupati - Self
IshAna - sun
mahAdeva - moon

The eight forms of shiva are defined as follows:
sharva - that form consisting of the earth, that holds the entire universe of the mobile and the immobile beings
bhava - that form consisting of water that enlivens the entire world
ugra - that form which holds the outer and inner universe and throbs by itself
bhIma - that form consisting of the firmament (AkAsha) that pervades everything and affords space to all and causes the differentaition of elements
pashupati - that form which is the support of individual Selfs and abiding therein splits the bondage that encircles them.
IshAna - that form which brightens the entire universe in the form of the sun
mahAdeva - that form which is like the moon of nectar-like rays that strengthens and fattens the universe to satiety
rudra - that form which pervades the entire universes and is most subtle

शिव अष्टमूर्ती पूजा
एते गन्धपुष्पे ॐ शर्वाय क्षितिमूर्तये नम: |
एते गन्धपुष्पे ॐ भवाय जलमूर्तये नम: |
एते गन्धपुष्पे ॐ रुद्राय अग्निमूर्तये नम: |
एते गन्धपुष्पे ॐ उग्राय वायुमूर्तये नम: |
एते गन्धपुष्पे ॐ भीमाय आकाश मूर्तये नम: |
एते गन्धपुष्पे ॐ पशुपतये यजमान मूर्तये नम: |
एते गन्धपुष्पे ॐ महादेवाय सोममूर्तये नम: |
एते गन्धपुष्पे ॐ ईशनाय सूर्य मूर्तये नम: |

শিব অষ্টমূর্তী পূজা
এতে গন্ধপুষ্পে ঔং শর্বায় ক্ষিতিমূর্তয়ে নমঃ |
এতে গন্ধপুষ্পে ঔং ভবায় জলমূর্তয়ে নমঃ |
এতে গন্ধপুষ্পে ঔং রুদ্রায় অগ্নিমূর্তয়ে নমঃ |
এতে গন্ধপুষ্পে ঔং উগ্রায় বায়ুমূর্তয়ে নমঃ |
এতে গন্ধপুষ্পে ঔং ভীমায় আকাশ মূর্তয়ে নমঃ |
এতে গন্ধপুষ্পে ঔং পশুপতয়ে যজমান মূর্তয়ে নমঃ |
এতে গন্ধপুষ্পে ঔং মহাদেবায় সোমমূর্তয়ে নমঃ |
এতে গন্ধপুষ্পে ঔং ঈশনায় সূর্য মূর্তয়ে নমঃ |

References:
1. Any standard "Nitya Karma Paddhati" Puja book in Bengali
2. Shiva Purana : Book 3 : Chapter 2 : Verses 1 - 17

ॐ नमः शिवाय - ঔং নমঃ শিবায় - auṁ namaḥ śivāya