Adobe Premiere Elements has a free trial offer, although I'm not sure what limitations the "trial" imposes. Unlike many consumer based programs, it can handle unlimited video/audio tracks and real-time video rendering. The full version is available for about 100$.
Pinnacle Video Spin is free, but is also known for being buggy/crashing
Almost all non-linear editing systems use the same concepts and workflow...it's just a question of figuring out where the buttons are as you move from system to system. Check here:
http://en.wikipedia.org/wiki/Comparison_of_video_editing_software...for file format compatibility if you already have imported footage.