Heh, I've done a little of that myself. Been working on one for awhile now but got a little side tracked. Basically there's only 2 programs you need to make a video. But I havent' tried doing any special effects yet, so you may need another program, however the second program I list here can do a lot of stuff including effects
GeekPlay (or SK Player)
VideoMach II
I don't have the websites handy, but a google search will find the links for you quickly enough.
Now the basic way to do this is start a demo in "Viewdemo" mode with the GeekPlayer (or SK Player) and get to a point about a second before where you want your clip to start at, a little overlap is good here. Now open the console and type "startmovie 30 <FileSequenceName>" I think that's the format you need. The 30 is the FPS of your clips, you can make this whatever you want. then close the console and hit play, it will run very slow since it basically takes a screen shot every 30th of a second and makes a stream of screenshots.
Then open Video Mach and hit File->Open. Then select the first clip in the sequence and hit open. In the next dialog box hit "open sequence starting with this file" and it will open the sequence. Then add an audio file if you wish, and othe sequeneces, be careful to add your sequences in order. I recomend doing just 1 or 2 to begin with until you get your formats down and the output the way you like. Then Select the little blue floppy disk icon in the center (next to the play button) to pick your output settings
For format I recomend Avi (since it lets you do DIVX ) Then Hit the video tab and in the bottom right corner select "Format Options" Chose your codec from the list that opens up (again Divx if you have it installed will be there, as well as any others you have installed, exa xvid) Also you may need to play with the bitrates of the divx configuration settins. Higher BitRates = better quality + bigger filesize. So play with it to your liking.
Next chose your output resolution, this works best if you made your demo in your output resolution, but that isn't a requirement, it can reseize as needed quite nicely. I recomend around 640x480 or 800x600.
Chose any audio options you like and close the box. then set any output video effects (text, color adjust, fading, etc)
Hit the play button to start the processing and it should opent he file when it's done.
Congratulations:boing: , you've just made a cs movie. enojy!!