I'm attempting to drill a lot of holes in a galvanized steel garbage can. I'm finding it easier just to put nail holes in it, but of course they are not large enough.

Should I just get a fatter nail, or am I going about this the wrong way:confused:

A Nail could work for starters, then a Unibit or Stepped type drill bit. A pilot bit will help keep location accurate, a Large bit may want to grab. For thin metal, a Stepped type bit could do well.
An example:
http://www.irwin.com/irwin/consumer/jhtml/brandProducts.jhtml?brand=Unibit

Just pop-it with the nail as a starter and finish with the drill.
Same advise as strato.