CAD Files

I am new to this and if I am in the wrong spot forgive me…
I am a foot doctor and having fun with this CGI stuff. I am starting to get a hang of the basics of Blender. I did see Bucky Bunny and some of the other open source films being produced and would like to use this medium to help my patients better understand how the foot works. I have 3D CAD files of the foot and wondered if there was a way to import it into the blender/Gimp format and use these programs to animate the foot. These are actual bones, true in size and shape, so it would allow me to be very accurate if I could animate this project without distorting it with my artistic inaccuracies.

Welcome to BA.

depending on the format you got your cad data it is very much possible.
import options are better in 2.49 than 2.5, however I suggest you get MeshLab (opensource) it can convert between a good sorted list of mesh formats. And if your data is solid data there are ways too.

I have ASCII, Binary, CAD and STL files of these bones. I have meshlab. How do I convert to a functional Blend or Gimp File?

Gimp is a pixel based image editor, no converting to gimp.

For blender my first choise would be to convert the STL to a Wavefront .OBJ
Or directly import the STL in Blender 2.49, save the .blend and open in Blender 2.5

Can anyone tell me how to import my CAD files into blender so I can can animate it?

What kind of CAD file do you have? The scripts for importing outside files are located under File > Import >.

Open Blender 2.49
Go to file>import>STL

import your STL file (Blender 2.49 can import STL directly)
Save the blend.

open the .blend and edit in whatever blender you want.