I love maps, especially maps with canoe and/or backpacking routes on them. I ordered a few from Federal Publications last week and they came the other day. I only humiliated myself a little bit doing a little dance and squealing at the mailbox.
here. This new map covers the entire Temagami region (which apparently the Ontario Parks one doesn't...I haven't had much time to study it thoroughly because there is a lot of information on it) including 14 parks, 21 conservation reserves, 4000km of canoe routes, 450 portages, 1100 campsites, 60 access points, 47 viewpoints, 10 hiking trail networks, and the locations of 30 stands of old growth pine. As impressive as all this is (and okay I admit I want one!) We aren't really experienced enough to need a map that extensive yet.
Halfway Lake and The Massassauga, on the other hand, very good options for our level of tripping experience. Both areas have relatively short portages (the shortest in Halfway Lake is about 720m) are accessible and within a reasonable distance from home. I'm really looking forward to checking them out.
Finding maps can be a bit of an issue. Most of the time you can find them in the local MNR office, or if your backcountry trip will be inside the boundary of a Provincial Park, you can get maps at the park's gate or store. Algonquin's Visitor's Centre sells maps that cover the area in and around the park, but if you want to plan a back country trip, you most definitely want to study the map in advance so you can plan the trip and book sites.
Some of your best resources are "Friends of" websites. They will often have a store or publications page where you can buy maps.
Friends of Killarney
Friends of Algonquin
Friends of Frontenac
Friends of Quetico
Friends of Temagami
Here are some other sites that sell maps
Federal Publications This site sells maps for all provinces, as well as many other publications on topics like politics, taxation, religion and personal finance.
Chrismar Maps These are the people that make the Adventure Map series (see the Halfway Lake map in the photo above) They are waterproof topographic maps, and are very clear, and compact with details like campsites, portages, and even what kinds of fish are present in each lake.
Of course, if you have an outdoors store or outfitter in your area that sells maps, they will likely be able to order you ones for the area you are interested in. For the most part, stores stock maps for their area, so it's doubtful you'd find a map of the far north being sold in an outfitter in central Ontario. But if you ask, they'll probably be happy to order one for you.
I'll be posting more resources like this as I come across them. If you have a good resource for maps online, please let me know.