The Champlain Canal connects the Hudson to Lake Champlain, starting in Troy and ending at Whitehall. Counting the Federal lock in Troy, you will have to pass through 13 locks. You will be under power the entire way. After you get out of the Hudson and into the canal, you'll be cruising in a big, straight ditch.
You will have to step your mast before you get to Albany as there is insufficient bridge clearance from there on. Many persons have their mast stepped in Catskill (Riverview Marina or Hopponose), although there used to be a do-it-yourself crane at a yacht club in Castleton. You can re-step your mast when you leave the canal.
Passing through the locks shouldn't be a big deal. After a couple, they become pretty routine and the lock tenders are usually quite pleasant and helpful. Having one person stay amidships with a 50 ft. line, while you stay at the wheel, will make for an easy day. For a vessel your size, one line will be all you'll need to secure your vessel to the lock wall (either a ladder or a vertical pipe). Your line-handler may also wish to wear a pair of gloves.
Just make sure you've got fenders out on both sides. Some cruisers will pick up burlap sacks, fill them with straw, and use these as fenders. The nice thing about this method is that you can empty them out and fold them away when you don't need them, or even throw them away.
In order to enter the canal you will need to purchase a cruising pass from the State of NY.
Good luck your boat search and enjoy the canal!