Thats kwl man!!
If you have a scale model or blueprints of a tank, you can drwa your own plans using basic math

( The way I drew my plans, only had a picturebook)
Here is a site for tank blueprints
http://www.the-blueprints.com/blueprints/tanks/
TOP TIP : Remenber all your motors, battery and electronics must fit into your tank so it would be clever to get all the parts and components first, set them out as they would be in your tank and detirmen the scale (size) of your tank based on how much space you need
Good luck on your build!