the link that Evan posted is probably super helpful, but here are mine (if possible, use Compressor and apply a Gamma Correction filter set to 1.2 under the video settings, it will prevent your colors from flattening when you export):
for personal viewing:
1. file>export>using quicktime conversion>options>video settings
2. compression type: H.264
3. Frame Rate: 24 fps
4. Key Frames: Every 24 frames
5. Date Rate: Automatic
6. Quality: Best
7. Encoding: Best Quality (Multi-Pass)
8. Press OK to go back a screen, then click Size under Video
9. select the size of your LOWEST quality HD clip (If I have all 1080p clips and one 720p clip, I will export to 720p)
10. hit OK to go back a screen, then click Sound Settings
11. Format: Apple Lossless
12. Rate: 48 kHz
13. Quality: Best
14. Hit OK, you are now ready to export. the streaming thing doesn't really matter for this export
for online:
1. file>export>using quicktime conversion>options>video settings
2. compression type: H.264
3. Frame Rate: 24 fps
4. Key Frames: Every 24 frames
5. Date Rate: Automatic
6. Quality: Halfway between medium and high
7. Encoding: Faster Encode (Single Pass)
8. Press OK to go back a screen, then click Size under Video
9. select the size of your LOWEST quality HD clip (If I have all 1080p clips and one 720p clip, I will export to 720p)
10. hit OK to go back a screen, then click Sound Settings
11. Format: AAC
12. Rate: 44.1 kHz (this is CD quality)
13. Quality: Normal
14. Hit OK to go back a screen, Prepare for Internet Streaming: Fast Start
15. you are now ready to export.