re: Lewis and Harks Montana Exp of 2012
Dharkin, hello and welcome.
Like Dave said, narrowing down your geographical parameters is probably the best way to start. There is nearly every kind of trout fishing your heart desires in Montana (big tailwater, famous and crowded, unknown and easy, remote, spring creeks, etc) and if you plan it right you can fish a little bit of everything (or whatever you want) all in the same relative geographical area.
I say relative because driving 100 miles to go fishing isn't a big deal on a Montana summer day.
Get a good map and study it for a while. You could go from Missoula to Bozeman, or Bozeman to Billings, or Billings to Yellowstone, or....lots and lots of options. But keep in mind, once you leave Bozeman area your B&B options are a lot less!!
Long and short: you could easily focus on one area (Missoula, Big Hole, Bozeman/Gallatin, Yellowstone, ect) and have more water to fish than you could do in 10 years. Trust me, I'm still working on it!