I bought mine off ebay but they come from www.iamlabels.com 2 labels per 8 x 11 sheet, rounded corners, white label with yellow backing paper. they were the cheapest I could find. I picked up the 600 sheet pack.
I got the Brother GL 570 Label printer to print mine. I LOVE IT! I don't have to worry about labels getting jammed in my laser printer. I don't have to worry about ink running from an inkjet. It is perfect, and has several label sizes to work with.