The black bear regulations are available here:

http://fwp.mt.gov/fwpDoc.jsp?id=48860

You can buy a tag over the counter and it'll cost about $370 because you're a non-resident. You don't need a guide. You will have to take the free black bear identification quiz. The FWP office in Bozeman can get you all squared away. I've seen quite a few bears in the Bridgers and up Hyalite. Just don't be an idiot and accidentally shoot a grizzly...unless it's the University of Montana variety. Go Bobcats!!!

Good luck.