We were looking for some shelves that let the books face out so our kids could see the fronts, since they can't yet read the titles on the spines, and they were all very expensive.
Someone gave this idea, and although I've lost the original link, I can explain what we did and show this picture of our playroom.http://www.purplestork.com/gutter.jpg
They are made from rain gutters!
For each shelf, you need one gutter, 2 end caps, and enough middle brackets to go on each stud, or at least every other stud. The gutters we use are sort of half-hexagon shaped. Lowe's had them, and the end caps and the brackets all together.
Measure your gutter and cut it to length. (Used a hacksaw, took about 10 seconds.)
Use a level to mark where the brackets are going to go. I think we put one every other stud. Screw the brackets to the studs. Snap the gutter into the brackets. Snap the end caps on.
Put your books on and get ready for your kids to grab them right off, LOL!
Ours took maybe 30-40 minutes to install, max. The hardest part was finding the studs, because we didn't have a stud finder and had to knock on the walls and we mis-guessed a couple times. I think the cost of materials was about $25.
Also we had one really long shelf on the bottom, and there was a special bracket for joining 2 gutters together I think.
Ours have been up for a year now and are in great condition. We have a regular shelf with all the rest of the books, and cycle them in and out so the ones on the shelves are "fresh." The kids can't go through the room without spying a book they want to read!