They're not different species, they're color patterns based on geographic location; more commonly referred to as a strain. (I don't CARE what wikipedia says, there are many biologists that discount E. m. immaculatus/ohioensis and will classify all as E.m.masquinongy.
Tigers are a hybrid of muskie x pike or pike x muskie.
As was stated, it's a process, one which I've been at for close to 25 years and still learn every day. They have the most amazing way of frustrating you, and some days they do just what the books say they should. There's no hard and fast rule to answering any of your questions in terms of habit, habitat, or difference in size and appearance. There are times, for instance a Leech Lake strain looks just like a WI strain. There are times, as well, that WI fish are smaller than the LL strain and comparable sets of fish are different every time. They're weird, and that's just starting.
Get your hands on "Muskies on the Shield" from Pearson. If there's one guy that knows muskies better than anyone on the face of the earth, it would be Dick.
Also, be prepared for what you're getting into in terms of tackle. The Bass bait monkey has NOTHING on the Muskie Bait Monkey. I literally have a safe for my muskie baits. Literally. I keep them in a Browning fireproof. I've got some 300 jerkbaits and pull baits, all are wood. Add a some plastic to that and you're talking 500 baits. Add in bucktails... well, you get the picture.