Well, the slots are for the biscuits of course! I know Jon's thinking--what in the heck is a biscuit?!!??! Well, this is a biscuit:

You use these slits in the wood to wedge this little biscuit of wood into. If you have two pieces of wood (see below),

then you can put two pieces of wood together. It's a form of jointing. It's a woodworking skill--like nunchakus skills, or bull riding skills--only better! OK--so once you put the two piecs together, you just put some glue in there before hand and BAM! You've got a corner!!! Remember, each piece here took at least 5 cuts each just to get the shape right, then it took another two biscuit cuts to make room for the biscuit! It's a LOT of work.

So once you're done with them, you just make 3 more set--or if you're a beginner woodworker like myself and screw up on them over and over, you make 7 more sets!!! As you can see blow in the plans, it should only take 4 sets and then you cut some more wood for the front, back, and sides and it should look something like this picture:

So what does MINE look like now??? Well--check it out!