Mum24kids is right; the folks in your state tax office are the best resource. First, remember that that PTO is a business entity, hopefully a non-profit, but a business all the same.
I know it can all seem confusing at first, but keep in mind that everyone legitimately selling goods in your state - from a small stand at a flea market to big companies - deal with this all the time. The tax office that handles this should be used to bewildered small business owners with questions just like yours.
It appears from a web search that the Kansas Department of Revenue is the governing agency in your state. They should have people and publications that will help you. If you are not already registered as a business in your state that will be one of the first steps.
Here the questions you need to consider:
1) What process is required to become tax-exempt in your state? (If you qualify, you want to do this.)
2) If you become tax-exempt, how does it apply? On things you purchase? Do you have to collect taxes when you sell something? When/When not?
3) What is the appropriate tax rate? You have to consider state PLUS local. This is easy to find out. It will be some percentage and you can often even get printed charts if you need them.
4) How and when do you need to file these taxes?
It will take a bit of homework to get these questions answered, but then it's pretty easy.
For example, here in Texas we can have two days (events) where we don't collect taxes if we are approved as tax-exempt. So, naturally, we choose the two with the biggest impact. (Not everything is taxable, so that's a consideration also). Then, for sales of other things (like T-Shirts) we fill out a form once a year stating that we had $X in sales. We include a check for 8.25% sales tax, and we are done. It's not hard. (When we set the price for our T-Shirts, we keep in mind that we'll have this expense later, so we make sure the price we charge will cover it.)
Here are some links that might help you:
Sales Tax Exemption Information and Certificates (KS-1520) {Publication, see the section starting on page 6 for some general info; page 36 has the PTO form.}
www.ksrevenue.org/pdf/forms/pub1520.pdf
List of publications and documents
www.ksrevenue.org/forms-bustax.htm
Contact info:
Telephone
Kansas Tax Assistance
-(outside Topeka) 1-877-526-7738
-(in Topeka) 368-8222
www.ksrevenue.org/
Good luck!