1.Upload all of your video snippets from your digital camera, and then open the two clips that you’d like to combine into one short movie by double-clicking on their file icons or by using the Open command in QuickTime. Place them side by side.
2.Use the Trim command to snip off any unwanted footage at either end of your movie. Simply move the bottom triangles on the scrubber bar to the endpoints of the content you want to keep. The gray area will be kept, and the white area on the scrubber bar will be trimmed away. To make this happen, go to the Edit drop-down menu and select Trim. Repeat this process for both clips.
3.Now use Select, Copy, and Add to combine these short clips into a longer

Next, click on the second movie once to bring it forward. You’re going to copy the content of this snippet and add it to the window on the left. Open the Edit drop-down menu and choose Select All, and then open the menu again and select Copy. That will put the selected video and audio on the clipboard.
Finally, click on the first window once to bring it forward, and choose Add from the Edit drop-down menu. The video you previously copied to the clipboard will be added to the end of your first snippet. Notice how the time designation has changed to reflect the addition of the second snippet .
presentation. The procedure is similar to copying and pasting in a text document, but with a slight twist. Start by going to your first snippet and clicking on the far-right control button to move the scrubber head to the end of the clip. (You could manually drag the scrubber head there, but this way is faster.)

If you want to combine more than two clips, you can keep adding snippets as described above until you have a complete movie. Always work from the beginning of the movie to the end, adding video clip after video clip, and be sure to trim your snippets before adding them to the movie.
Once you’ve combined your clips into one movie, go to the File menu and select Save As. Give your movie a new name, click the “Make movie self-contained” radio button, and then click the Save button. You now have a complete movie.

VideoPad Video Editor Software
http://www.nchsoftware.com/videopad/index.html

Pinnacle Spin:
http://www.videospin.com/Redesign/

VirtualDub: Mostly for working on avi and there are lots of filters.
http://virtualdub.sourceforge.net/

Wax: Oldie but goodie
http://www.debugmode.com/wax/

Cinefx:
http://www.cinefx.org/downloads/

Zwei-stein: has not been updated in a while.
http://zwei-stein.en.softonic.com/

Avidemux:
http://fixounet.free.fr/avidemux/download.html

For the home users they have a “budget” version Pinnacle Studio HD.