I started to organize my books in bins a la Beth Newingham. (http://hill.troy.k12.mi.us/staff/bnewingham/myweb3/) However, I'm really torn about how many books I should level, if I should level them at all. We do many lessons throughout the year about choosing just right books, and some students get a stronger grasp on this concept than others. I like them to try to choose books independently, but they need so much help at the beginning of the year that I thought leveling them the way Beth Newingham does would work well. I don't want a stigma attached to the "red" books or something like that, either. How much of your library do you level? Do you put the guided reading level (letter D, for example) on the book or do you use a code like Beth Newingham does?