This is a quick basic direction for how to make a very rudimentary, and quick, Plywood shelf. I made this at Techshop SF using the table saw, dado stack, band saw and belt sander. In all reality if you have the table saw with a dado blade, you will be fine.
I used 3/4 inch prefinished ply that I found in the scrap bin, so really anything big enough, and strong enough to make your shelf will work.
Step 1: Cut sides
First step is to cut your side pieces to the right length and width.
I took the extra step of rounding off the top front corners with the belt sander just for aesthetics, but this is by no means necessary.
Set the fence on the table saw to your desired width and rip away, when cutting the sides to length, I used the cross cut sled, but you could use the band saw as well, or just be super super careful. If you are not comfortable and knowledgeable cross cutting on a table saw, I highly recommend using the sled to save yourself stress and potential injury.