Definitely start with some Youtube tutorials on this. No sense us retyping it longhand here for you!
If you run into specific scripting issues, hurry on back. When you do, here is how to report your problem productively in the Unity3D forums:
http://plbm.com/?p=220
How to understand compiler and other errors and even fix them yourself:
If you post a code snippet, ALWAYS USE CODE TAGS:
How to use code tags: Using code tags properly