Vancouver is awesome, great choice - I'd suggest going to Whistler if you like snowsports or mountain biking but there are several mountains even closer that are well worth a look although I was there over summer so it is difficult to tell properly.
I booked a hostel for the first couple of nights but had no plans for beyond that point so I could afford to be flexible. Granville Street has at least 3 or 4 hostels on it and is quite busy at nights with a decent selection of food so I'd recommend that as a starting point if you don't have any better plans. The BUNAC offices are also about a 10 minute walk through downtown from there. Stanley Park is a good way to waste a day just wandering round (actually maybe rent a bike or rollerblades), Deep Cove is good for watersports and Vancouver Island has a great fresh food market as a few examples of things worth doing.
Craigslist is quite good if you are looking to buy stuff and/or rent housing. If nothing else the Rants N' Raves section kept me amused - I won't link to it due to swearing etc but it isn't exactly hard to find. I believe the jobs section on there is quite popular but I just went with an agency for simplicities sake.
I don't know exactly how much I can pass on in the way of tips about job hunting or flat finding, I walked into an agency one day, had the tests and was at my job the next day. The job was a company that placed foreign students in homestay accomodation - they took a shine to me so set up a place for me and bought out my contract with the temp agency after less than two weeks so I'm probably not best placed to comment on how to do it.
However what I would say is to be as open to options as you can be and don't be afraid to ask for help, - crass generalisation coming - Canadians like to be helpful so will try and figure out something to get you sorted so just from chatting to folks in bars I had an offer to be a warehouseman/longshoreman if I didn't get something else sorted and that was without even trying.