Video, internet---codec questions!

Hi gyes!
got my canon xl2 since 2 month now.
And i need to learn a lot about the different filetyps and codecs.
I´m already very happy with my camera-settings and presets.
I alway export the footages with premiere pro cs3 in "microsoft DV-avi" format first (with a very good result)
Then i converted it to DivX and uploadet it to Stage6.com
The codec is really great, because you don`t really lose quality even with a very small filesize! Stage6 shutts down on the 28th of February! And i didn`t find any other site, where u can upload and playback DivX.
I also have an account on Blip.TV... u can upload almost every filetype there, but the problem is, its all getting convertet to Flash! and i lost detail, color and gamma a lot! have a look http://mansek.blip.tv/#700238
What do you know about the H.264 - codec, and wich programm can i use.
just tell me, what you know about the different codecs....and possibilities to get good results on the internet! Thanks a lot

Chris
Vienna