Where does everyone buy their supplies. Cake circles, fondant, cake boxes, etc...

I buy a lot of my cake circles and boxes online from The Baker's Kitchen.  There's no minimum that you have to buy, but if you reach a certain $ amount, the shipping is free.  I usually do 1 large order at the 1st of the year and get the free shipping and that pretty much lasts me for the year. 

It depends on how much you use really.  Sometimes just getting them locally at places like Wal-Mart; Smart & Final/Gordon's type store or cake supply shop is good enough.  Other times what GJsLady said.  There are other on-line suppliers so google 'cake boards' or such and see what comes up that's best for you.