Here is a brief tutorial for creating time-lapse movies in MAC OSX using QuickTime Player. The steps may be different for those using Windows PCs. I highly recommend paying the minimal fee to make your QuickTime player a fully unlocked pro version.
1) Shoot your photos at the size/resolution that you want for the frames of your movie (i.e.: 640x480). Set the camera on a tripod and use a remote to snap each frame, or set it to shoot a frame every 30 seconds or so. Choose the best possible angle and lighting. You many need to tweak your camera settings.
2) Transfer the files to your computer.
3) If you want to add any blank or title frames, make them the same size as the photos in your editing software. They have to be named the same way the camera files are an in proper consecutive order. Very important! Depending on what frame rate you want, you'll have to make duplicate images so that the title or blank spaces stay on the screen long enough. Each file has to been name consecutively, even the duplicates. This part is time consuming but necessary. Save them to the same folder with the rest of the time lapse photos.
4) Open QuickTime Player. Go File > Open Image Sequence... and choose the file that is to be the first frame. It should be the lowest name in the file order, i.e. P6623 and not P6648.
5) Choose the frame rate you desire. I found 6 is good for time lapse but 10 also works if you have several hundred frames.
6) You now have your QuickTime movie.
7) To add sound, choose File > Open File... and pick an audio clip compatible with QuickTime (MP3 works). Keep in mind copyright issues, it may be best to choose royalty free public domain files for commercial use. Musopen.com has a good selection or you can record your own music.
8) This would be a good time to trim the audio to fit your movie. To do this, adjust the little tabs in the time bar at the bottom to the length of your time lapse movie. Go to Edit > Select All and then Edit > Copy.
9) Click back on the time lapse movie window. Click on the time bar and open the tabs all the way to either side. Go to Edit > Add to Movie. If you audio is longer than the movie and you want it to fit, choose Edit > Add to Selection and Scale. This will cause the audio to either play faster or slower to fit the length of your movie.
10) Click File > Save and save it as a Self Contained Movie (.mov). This can be uploaded to YouTube. You can also File > Export... or Export for Web... if you want to fine tune the file even further or be imported to iMovie for voice over and other effects.
There you have it, a down and dirty Time-Lapse creation tutorial!