Do I need to use heavier paper (ie, 30 lb) for labels? Would regular printer paper work just as well?
I would recommend getting label paper with the adhesive already on the back, like this stuff. Otherwise it's going to depend on your glue, though based on the thickness of the label paper you'll probably want at least 28 lb. If you'll be printing on an inkjet, I'd also recommend getting some of this to waterproof them.