Windows 7: Optimizing streaming quality of my encodes... very confused

Sorry if this is the wrong section...

I'm trying to maximize the quality of my Youtube uploads and find myself struggling. I have no idea what there criteria is when they re-encode your videos; it seems random.

Advanced encoding specifications - YouTube Help

At first it lists 8,000kbps max bit rate. Anything more than that and it starts compressing. Yet it then lists 50,000kbps as "high quality".

What exactly should I be doing here? If I upload at 15k vs 12k, will the video quality be better? Or does it really not matter between 8-49k, and only matters once you pass 50?

So confused.

Im not sure it matters.
Youd be luck if any HD video on you tube actually played back at 1500 or more (which isnt even DVD quality)

Anything you upload will get compressed a great deal, and the quality will suffer,compared to the original