I made a model, got it into Fo3, but the textures from 3ds max don't work. So can someone give a quick tutorial, or the link for one, on how to UV map and texturise with GIMP?

This is for autodesk 3ds max 2011 x32 bit

If your using procedural materials in 3DS Max (not baked to a single texture file), then no those wont export. You can bake them down but id recommend Xnormal for that since its a bit easier without the myriad of settings.

For UVs id recommend looking into HeadUS uvlayout, its far more intuitive to unwrap in. Tuts can probably be found on youtube. But its fairly simple really, just a few hotkeys and your off. Most of it is automated, and features color mapping to indicate areas of distortion.

And just to be clear dont bake anything until youve taken care of your UVs.

One topic is sufficient - it saves confusion with answers.

http://www.gamesas.com/index.php?/topic/1115414-how-do-you-import-a-nif-file-into-the-geck/