Most school indoor sports venues are pretty dark so I typically shot indoor sports with nothing slower that an f2.8 lens and only when I have to have the zoom factor. Most of the time I opt for faster primes as the college venue I shoot in has decent, but not great lighting. The 85 f1.8 is a constant for me shooting basketball along with the 35 f1.4L.
Stopping action requires fast shutter speeds. 1/250th is the minimum for something like hockey, basketball etc. Slower and motion blur begins to creep in. I prefer to shoot a no less the 1/320th with 1/500th my target. To get those shutter speeds you are going to have to bump your ISO up. Possibly as high as 3200.
Keep in mind that you will probably have a lot of noise in your shots if you have to go to 3200 ISO. If you shoot in raw you can post process a lot of that noise out. This will soften you shots a bit in the process. One of the best ways to reduce noise from high ISO is to have the exposure dead on.
If you can set a custom white balance before hand, I would suggest that you do so. If not adjust it in post processing. If the lighting happens to be florescent also be aware that you will probably get some color shift in your photos. That is just the nature of florescent lighting.
If you have never shot sports before I would suggest that you set your camera to full time focusing. Canon calls it AI Servo. Follow the action at all times with the camera constantly focusing on the action. Use one focus point. I normally use the center point.
In the custom functions set you focus to the * button on the back instead of on the shutter button. Don't remember the exact CF# on the 30D at the moment so check the manual. This is easier to do and be prepared to trip the shutter than keeping it all on the shutter button
You have to be prepared to get the shot by tracking the action with the camera constantly focusing on that action. If you don't and see something you want to shoot, by the time the camera focuses the shot is gone. In tough conditions like this it is better to have a shot that is in focus with noise in it than a shot that is blurry because you wanted to reduce the noise with a lower ISO that affected your shutter speed.
If you feel comfortable shoot in manual. If you do not feel comfortable shoot in AV mode. Yes shutter speed is what you need to keep high, but you also want a want to control you aperture so that all the action is in focus but the background, crowd, etc is out of focus. That can be the difference between a nice sports shot and an outstanding shot, by making the action pop off the photo. In AV mode you control you aperture directly and your shutter speed with the ISO. Need more shutter speed bump the ISO up.
If you by chance have a hand held light meter, get there early and meter the court. Most courts have pretty even lighting. Find the darkest area of the court and set your exposure for it. You should be good for the entire court this way unless they have very uneven lighting.
If you have a chance, go to a practice or two and get some practice time in yourself. Every fall I start by going to the preseason practice sessions at the local college I shoot for to get some practice time in myself. Sports photography by it's very nature is very demanding both in terms of equipment and on the photographer. It, at least for me is also one of the most enjoyable. Good luck.