Rule 1. doesnt matter what you spent on your equipment.. its only as good as your knowledge on how to use it.. thats wut i learned my first couple box's..
Tips: if you use screws space them about 3-4" from each other. screws actually weaken a box. but are great to hold it into place while building it. (once u put screws in might aswell leave em in).
Use titebond for glue 2 or 3 is good.
Dont use less than 3/4" thick wood (MDF will be the cheapest bet for learning with)
Invest in a few clamps