Baby sketchbook: a sheaf of paper of medium weight to be used for drawing, usually close to the dimensions of three inches by five inches.
More about the Cult of the Baby Sketchbook

Ali's Baby Sketchbook:
Drawings, paintings, & sketches from various walks of my interesting life

Old work: All artwork from before the creation of the Baby Sketchbook website...that is, the artwork I've saved. Which means that mostly it's work from 9th and 10th grade, since I didn't scan anything I produced before that.
Schoolwork: All the work (that I consider halfway-decent) that I did for my AP Studio Art III class in 11th grade. Includes my concentration, as well as breadth pieces done during class.
Sketches: Doodles in margins on school worksheets, baby sketchbook drawings, or preliminary sketches for larger works, stuff I don't think is special enough to be in another section - it's all in here. Some are random, some are funny, and most took less than five minutes ^_^
Fanworks: Non-original characters in here. So far, it's all anime fanart. I'll be sure to let you know if I change that. Stuff in here falls into "scribbly fanart that IS fanart so it's not in the 'sketches' section" or "high-quality fanart that IS fanart so it's not in the 'other' section" or somewhere in between. Also where I post my doujinshi (Japanese; basically means 'fan-comics').
Other: Normal art and stuff - things that don't fit into any other category. There's not too much of this, because while in art I usually do everything FOR art class, but enough to deserve its own section.