D90 settings for stage ballet

I have had my D90 for roughly 2 years and have had great luck with it. I need some help - two part question, totally related.

First, is there any kind on online photography course you could recommend - free or low cost would be great. I love photography, and have taken some fine shots, but don't have a good working knowledge of the manual settings available (D90 or any camera), how to use them, or how to use them together to meet a visual goal.

Second, I will be taking pictures of a live ballet performance in about a week and have recently run into problems with my stage shots looking too 'hot' - whites look like they are burning up the film (see picture included). Since this performance will be Swan Lake, there will be lots of all black and all white costumes. I need to catch the dancers in mid-turn, mid-leap, and mid-kick so I need to have a fast enough speed to freeze them.

Can any of you help? I know that I need to learn about all the key photography elements, but for the upcoming show I just need some short term help on settings. I have a 28mm1:2.8 and a 50mm 1:1.8 that I usually use for these shows depending on where I can be placed in the theatre.