Muskies are known as "the fish of ten thousand casts." That number is an exaggeration, but they very well could be the most difficult freshwater fish species to catch in North America.
But how hard are they, really?
That depends. Would you be happy with a 30"? Or would it take a 50", like we see in all of the magazines?
Do you want to catch one casting? Or trolling? Would you mind hiring a guide? Or do you want to do it yourself?
Catching a 30" muskie isn't too difficult. Its more difficult, however, than catching a similar pike, and more difficult than an average sized bass or walleye.
If you want to catch a 30" muskie casting. Then you could hire a guide for 2 or 3 days in the spring and probably catch one. Maybe you'd catch more but one in 2 or 3 days would be a good expectation.
Much will depend on where you fish. If you just want to catch a muskie casting, then you'll want to find a shallower, weedier, darker lake, or part of a big lake, and fish it in the spring. You'll not catch a big muskie this way but it would be your best bet to catch a muskie while casting.
What you'll do is cast Rizzo Wizzes and Rapala Original Floating Minnows
(jointed or solid) around the lake at the edges of the weeds. Don't be surprised to catch a few pike this way either.
Catching a muskie while trolling will be easier if you are already familiar with trolling for other species, but will be harder than casting if you don't already troll. Trolling will also require more equipment. And there are more laws around trolling. Many places do not even allow motor trolling. While casting you'll eventually stumble across a fish; if you are going to troll I really would recommend a guide for your first day.
There is one big benefit to trolling, and that is: trolling is what you would do if your goal is to catch as many fish as possible.
If your goal is to catch a 50", like all the fish we see in magazines, then the first thing to know is: Magazines are nothing but pictures of things that you can't have.
But catching a 50" muskie is possible.
If you want to catch a 50" muskie, then you should either troll Lake St. Claire, or cast Sabaskong Bay in the Lake of the Woods. (Note: If your goal is fishing do not schedule your fishing trip to Northwest Ontario, Lake of the Woods, etc. in August. August is the worst month to go fishing in NW Ontario.) Know that while these are the two easiest ways to catch a 50" they will almost certainly be thin fish.
If you're trolling drag as many bucktails and crankbaits as you are legally able around any structure that you find.
If you're casting Lake of the Woods (LOTW), then get whatever baits that look good to you in the store or magazine. Then cast them around the structure you find. Islands and points that are adjacent to deep water will be good bets.
You could go your whole life without catching a 50" and the kid fishing for bluegills could catch one tomorrow, but that's how fishing goes.
Catching a muskie isn't impossible, but it will take a considerable amount of time. Hire a guide and you'll cut your learning time down dramatically.