Do some reading before jumping in to this.
Using Google search: changing ip addresses+configure+linux network
With that search I found a good list of links that match what your request. If you use the same search and read whats in those links you will learn a great deal. My recommendations are below.
Here is what your looking for:
If you go to this link (The main index for the guide above.), you will have the scope of IP layer at your fingertips:
(Feel free to alter the url to its main page and check the links.)
Good luck and feel free to post back with questions.