I've searched all the forum and the posts about this are not very elucidative, at least for me , so I really liked to know how can you record a mission with video and sound.
Does anyone know?

1. Create a track file: Fly a mission using Ctrl+R (record)
2. If you need to be sure you got the right action on the track you can play it back (Cntrl+P)
3. Edit the track (Video Edit Cntrl+E) to change any views or angles you need to get the action displayed the way you want.
4. Render to video using Record AVI.

Always best to start small, something on the order of a 15 second clip, to practice editing the views. Most people make small clips pieced together to build a complete video.

For advanced movie making tips you'll have to look through the Movie Makers forum and wade through all the different possibilities and options scattered there.

Thanks WhiskeyRomeo, I'm going to try that.

Beyond the basic (and free) tools already in Lock On many people prefer FRAP for step 4 and using editing tools like Sony Vegas or Adobe Premier for advanced editing features.
For someone just getting started Windows Movie Maker is a free program that lets you easily build and edit a video.