I also deduct my shoes, because I only wear them to teach in. I will deduct some clothing that I only wear to teach in. The IRS's thinking is that if you can use it outside of your group fitness job then it really shouldn't be deducted, but even if you get audited they will just assess tax on the deductions if they decide to disallow them.
And of course as previous posters stated, the music, vidoes, continuing education, etc. and anything else that relates to your fitness job should be deducted. You can also deduct your mileage. The rate for 2002 is 36.5 cents. So if you drove 1000 miles for work your deduction would be $365. Remember, you have to pay Self-employment tax in addition to regular income tax so deduct everything within the realms of the law!
The schedule C is simple- just put the amount from your 1099 on the "gross reciepts or sales" line, then enter your deductions below, or on page. 2 in the "other expenses" detail (part V). Enter your mileage info on page 2 of Schedule C (part IV), but times the mileage by .365 and enter that amount on page 1 under "Car and Truck Expenses" (part II, line 10).
Then carry your net income (or loss) to Page 1 of Form 1040.
If you use Turbotax it will probably guide you through this, although I've never used it.
I hope this wasn't too much info!
Cari