This specific topic has been covered several times.
This link has a good deal of FPSC specific programs.
http://forum.thegamecreators.com/?m=forum_view&t=116411&b=24
As for modeling programs, it depends on the modeling that you're doing. If you're planning on making characters, you'll probably want
Blender. However, if you're planning on just making non-moving objects, I would suggest
Google Sketchup. There are several excellent tutorials written by daarboven on how to import something from Sketchup's free version into FPSC.
For texturing programs, I would suggest either
Paint.NET or
GIMP. Both of these are very good programs and can be used to make some good textures.
For video capture, I would suggest
CamStudio. It's a freeware screen recorder that actually does effect the framerate that badly.
If you need anything else, feel free to email me or post on Gunn3r Games. It's good to see someone who is willing to learn these programs instead of the common attitude of "I want custom enemies, guns and segments and I don't know how to use any program, so I'm just going to bug you until you do something about it."
Gunn3r Games
