A: Ultimately, I would recommend that you visit all regions in Canada - The west Coast/Rockies, then the prairies, then Toronto/Niagra falls, then the east coast. Given a $2,000 budget though this will be next to impossible.

At minimum you'll need to budget about $25/night for hostel/lodging and $25 for food & drink (unless you cook all your own meals all the time or eat fast food everyday) which equals $50/day in hard cost or $1,000 over 20 days. So that leaves you $1,000 for overland transport and activities. Which will enable you to visit and see all the regions of Canada (mentioned above) but won't give you any money to do activities and side tours. To do that you'll need another $1,000.

If you don't care about seeing all of Canada then select one of the regions - the west coast is most popular with travellers and have the mountains, the prairies is the most off the beaten track experience and have the lakes, the Toronto area is a concrete jungle but is close to Niagra falls (if your into seeing water fall off a cliff) and the east coast is unique in culture and it too is off the beaten track.

I would recommend you try to see all of Canada, but you'll need a budget of $3,000-$4,000 (you're only here once):

Arrive in Vancouver and stay at the Samesun Vancouver backpacker hostel.  Take in the sites of the city for a couple days, then buy a CanRail pass from ViaRail - this is a hop-on-off pass from Vancouver (West Coast) to Halifax (East Coast) for $753 CDN.

Jump on the train in Vancouver and take it to Jasper. Get off in Jasper and stay at the HI-Jasper Hostel and take in the Rocky Mountains in Jasper National park for a day or two, then jump on the Moose travel bus to Banff (3 hrs south and $130 CDN return ticket). Stay at the HI-Banff Alpine Centre or the SameSun Banff hostel and enjoy the nightlife and Banff National park for two or three days. Leave banff and get back to Jasper to catch the train en-route to Edmonton. Stay at the Hi - Edmonton Hostel. Visit Edmonton for a day or two then jump back on the train and jump-off again in Winnipeg. Stay at the HI-Winnipeg Ivey House Hostel. Visit the highlights of Winnipeg for a day then jump on our 3-destination trip $199 that will take you into the cottage country where you can horseback ride, wakeboard, hike, and fish. Then jump on the train again in Minaki and take it all the way to Toronto. Stay at either the GlobalVillage backpackers or the Canadiana. See the sites in Toronto for a couple of days. Then take the day trip on Moose travel or Magic bus to Niagra Falls ($55 CDN). Get back to Toronto and jump back on the train to get up to Montreal. Stay at the HI-Montreal. See the sites in Montreal for two or three days then jump back on the train to get to Halifax where you should jump on four day Island Hopper tour guided by Salty bear Adventure for $259 CDN.

That's it. If you do all that you'll have seen ALL of Canada and be ready for home.