EC adj.on Rebel xt?

This cannot be adjusted while using "M" mode as stated on page 89 in the manual? I'm going to a HS basketball game tonight and wanted to further "mess around/explore with my new xt. I just always use M mode so I can control the AV & TV settings since everything I want to shoot seems to be low-light!
Another member mentioned f/1.8,1/500,1600 though I was thinking maybe 800 cause 1600 seems to high? any suggestions, TIA

Exposure Comp is an offset to the auto-exposure setting. In M, you'll just meter for 1 stop under or 1 stop over instead of using -1 EC or +1 EC.

Use whichever ISO gets you a good shutter speed for stopping the action. If the gym's bright enough that you ca nget 1/500 at ISO 800, then go for it. But if you need ISO 1600 to get that, then better noise than blurred photos.

Thanks Jon, I'll have to learn/understand this a bit more in the near future.