hey guys. my band is trying to find someone/place to design and print our band's merch. does anyone have any suggestions?
This is an international site mate, I could tell you who I use and it would be of no use as I'm in Australia. Ask other bands locally who they used, or alternatively use google to find companies that service your local area.
And no, Guitar Hero will not help. Even on expert. Really.
you will get far better results if you "buy" photoshop and start messing around with stuff. there are tons of tutorials all over the internet.

this really can be frustrating and take a lot of time, but it will be better in the end.

then take your stuff and go to a shirt printing shop near you. take the cheap shirts so you make a plus of at least 7 dollars if you sell them for 10.
unless you are in a band that has merch for 5 years cheap shirts will be fine.

and be sure to save up to 400 dollars because the more shirts you order the cheaper they will be.