For a bedside bookcase for my daughter, I patterned it off some toy shelves you can buy, but added a cove on the one side for a clock.

The construction is very easy - as usual, dimensional lumber, no rabbets or glue - just drywall screws from the sides into the shelves, which is plenty strong. This one was mostly made from scrap wood.

Overall dimensions:
Width: 31.5" - 31" for the shelf + 1.5" for the sides (3/4" x 2)
Height: 42"
Top shelf depth: 7.25" (1x8)
bottom 3 shelves are 11.5" deep (1x12)
back: 31.5" x 41.75" 1/8" plywood
flap 12" x 31.5" 1/8" plywood

approximate shelf heights:
Top Shelf: 7.25" deep, 41.25" to 42"
Shelf: 11.5" deep, 30.25" to 31"
Shelf: 11.5" deep, 17.5" to 18.25"
Shelf: 11.5" deep, ~1" to 1.75"
Kicker - a 1x2 on it's side

The holes in the sides make it look more like a doll house, and are about 3.25" wide and 4.5" high.  The top one is 2.25" wide.  All start about 4" from the front side to center them.

We used 1 5/8" drywall screws from the sides into the shelf - no rabbets or glue.  We used a counter sink pilot bit and used wood putty to cover the holes.  For a slightly less finished, but faster approach, you could skip the counter sink and just use a pilot hole, then paint over the screws.