If you do pre-registration for $50 then you get a ticket for the whole weekend, and you get access to the steampunk convention happening the same weekend at the DoubleTree hotel. Some perks to getting the ticket now are that it's the cheapest price you'll get (the price of a weekend badge will go up leading to May, and buying separate badges for the two days you're there at the con will cost about $10 more), and you won't have to wait in a long line at the convention buying individual day passes.
As for booking a hotel, sometime within the month Fanime should be posting the link for that. The rooms are discounted for convention attendees, and rooms have been blocked off specifically for us for when registration opens. Yes you could try to book a room on your own at one of the non-attached hotels such as the Fairmont or Saint Claire, but if they let you it's going to be more expensive. The hotels attached to the center such as the Hilton and Marriott won't even let you book right now because all their space is being blocked off for con-goers who will be booking through the site.
But overall, I'd say buy your ticket now and wait for the hotel site to pop up if you want to save as much as possible.