1. Take some flat pine boards, available at homedepot and lowes 1' x 8'.
2. Take a ruler and mark the lengths at which we will cut them. I cut it into four 1' x 2.5' and and two 1' x 3.75' pieces.
3. Cut them using the Saw Stop machine available at techshop.
4. Take the two longer pieces (1'x3.75' ones) and mark 3 sets of two placeholders for holes which will contain hooks to hold the shelfs. The hole sets can be 8'' apart and at a distance of 0.75'' from each other vertically.
5. Drill holes using the drill machine, and put the shelf hooks into them.
6. Screw together all the pieces as shown in the pictures.
And your simple shelf is ready.