I want to look into making one of these, but I'm not sure exactly what I need to make it. I know I need the shelf, velcro, and some kind of board in the back to hold it up. Also need some kind of side support, but not sure how to do that, so help there as well is appreciated.

Muchas Gracias!
I think you've listed everything you need... :/

glue, nail, screw or attach in some way a set of risers at the back if you want it to be angled..then paint it if you like, and velcro everything to it accordingly. I'm not sure what you're looking for really, as it's pretty straight forward

heres a link to a guy who bult one

you should probably be able to figure out whats necessary from that. Though really it's up to your own creativity