How to write an action plan for web development?

Can anyone outline what tasks would be needed for a web development business in an action plan?

Do you mean the following tasks:
1. User Requirements Gathering
2. Sign-off
3. Design / Development
4. SIT (System Integration Testing)
5. UAT (User Acceptance Testing)
6. MTP (Move To Production)
7. Go Live

You can have more to this.