Ok. First off you need to save your stunts. Im assuming youve done this already. You then need to put them into the GTA:VC/LC/SA user files section. Rename the replay to 'replay.rep'. Enter the game and hit F3. This will start your replay. When you see the stunt coming up, start recording. Use your mouse to pan the player and hold both Left and right mouse buttons and drag to zoom in/out. Once youve recorded the stunt, hit record again to stop. Record anything extra like cinematics.
Then you need to import the vid into a video editing program.
If your new, I wouldnt recomend Vegas. It can be quite complicated if you dont know what your doing.
Have a play about in Windows Movie Maker first. Do a few short clips set to music etc etc... Just get used to the interface, its generally the same through all editing software.
Once your happy with that get something like Ulead Video Studio 9. Its a simple program to use and easy to make vids in.
When you start to get serious about editing, then get Sony Vegas 6. Read a few tutorials from Daffy and mark and have a play around.
Also have a browse on the
www.own-age.com forums to help you with video editing
Basically the vid process goes something like this:
1.Stunt
2.Record stunts
3.Work out details about the vid, ie: Name, Music, Intro ideas etc etc....
4.Work out how you can arrange the stunts to fit the music
5.Insert the records into the program
6.Do any synchronizing, titleing and naming needed
7.Make the credits
8.Render the video using the best possible settings (Daffys is pretty good)
9.Upload the video to a host ie: TGA or Filefront
Hope that helps