VideoPad lets you combine video clips, remove segments, copy segments, insert still images, extract frames and insert them as images, adjust sound track level or remove sound tracks, insert a music sound track, adjust the brightness and contrast of a clip, use a wide variety of transitions, and apply special effects to clips. The free version creates .avi files which are fine for uploading smaller projects, but one reason I licensed the full version of the software ($69) was that it can output .mp4 files which are more compact than .avi and seem to load to YouTube better. For screen capture and inclusion in instructional videos I use Camtasia (big ticket software!) or Hypercam 3 (free) and then combine and edit video segments using VideoPad. Here's what the vendor's web site look like:
