Normals to an image with texture help?

I am still new to using normals and have great renderings with them but how can I apply that normal to a texture…

Instead of applying it to a texture and only seeing the effects of normals in rendering/GLSL how can I bake the normals to a texture and export it as jpg. to my desktop… If I put it like that
-So I would see a for example- http://www.darttinstitute.ca/img/behindthescenes/ninjaNormalsMap.jpg

That normal would be on this- http://satoworks.com/MasterClass/NormalMap.jpg
Then I can save that texture with normals on it to my desktop… ???

how would I be able to map that on a texture and then i can save it.

Thanks in advance

first you have to unwrap your model, then add a new image to your uv coordinates in the UV editor. then in the render buttons there should be some setting for baking. choose the normals option only, and bake. then save the new image, and you can then apply it as a texture channel.