I forgot to add, the Montana is a great bow, I have one in 55#s.
You said that you have never had a real bow. My advice would be to not start to heavy. I know the lightest weight the Montana comes in is 45# and that is still too heavy for a beginner. You need to develope good form and build up strength first.
I shot my 55#er quite a bit last fall, even after I got tired I wouldn't quit. Now I'm paying for it, I have tendonosis and can't shoot a bow. This could take months or years to heal. It's a curse that I have to deal with now.
If your just starting, do yourself a favor. Store the Montana and buy a lighter bow, a max. of 40 pounds, and don't over-do it.
Zack