Perhaps someone from Illinois will respond....here in Texas, you contact the State Comptroller's office or go to their website and follow the process. You will have to obtain a resale certificate, then report and send the tax collected to the State. Check with your craft show organizers and call your comptroller's office. Tell them this is once a year craft show that you do. Unfortunately, in my state, once you get the number, you have to file quarterly reports from now on...even if you are not selling anything. Waste of time and expense. In your case, you have to collect the tax according to their rules. It would be great if you could do a one time submission. Or perhaps you are going to continue selling throughout the year. Best wishes and have fun!