Well...let me see if I can help, since I am doing some programming to get our stores ready for this:
Any single item, purchased for your own personal use with a price of under $2500 is tax exempt on Saturday. If it is over $1000 there is a form you will need to sign for the DOR to say it is for your own personal use.
Items NOT included are: motor vehicles, boats, meals, telecommunication devices and services, gas, steam, and electricity.
There are a few caveats, such as bundled transactions (ie computers, if the price is less than $2500 it is exempt, if the price is more than $2500, but broken out ie keyboard, mouse, monitor, CPU, it is STILL taxable because it is normally sold together.)
This will also apply to layaways, so if you buy it, and pay for it on Saturday, but cannot pick it up or take delivery until later, you still get the tax benefit.
Any specific questions, fire away, I will do my best to answer them.