When I moved here back in ‘91, I lived with my parents in Beaconsfield (in the West Island) and my Mom would drive me around. That is until I could drive! I didn’t drive much, just around the West Island because I think you require a car to get around. I believe there was a bus that stopped close to my high school but I never needed to investigate.
When I started CEGEP (downtown) I had to take the train or, if I had to get home in a hurry, the 211 bus, which was pure hell as it has a lot of stops. Strangely, the train in the southern part of the Island is not nearly as punctual or have as many departures than the train that serves the more northern part of the Island, although this latter may have been replaced by the REM (Réseau Express Métropolitain). The REM is brand spanking new and is supposed to come every 10 minutes or so but there have already been some issues. If I had to move back to the West Island, I would choose a more northern part such as Pierrefonds or Dollard-des-Ormeaux (DDO)/Roxboro so that I would have access to the REM or their train. Once the REM brings you into town, you can take the metro or a bus. The MUHC built itself right above Vendôme metro station which is also a train station for the southern line (Deux-Montagnes). This makes it much easier to get to.
If you don’t know which bus or metro to take, consult Google Maps, Transit or Chrono. You will need an OPUS card to get around which can be charged by your phone! using Chrono! Children and seniors benefit from a lower rate and I ordered my son’s OPUS card through his school. A new one for adults can be purchased here.
I have also lived in Griffintown (a southern part of downtown close to Lucien-l’Allier metro) and now live in Notre-Dame-de-Grâce (NDG - yes, we love our abbreviations in Montreal!) close to Villa Maria metro. I was happy in Griffintown as I am in NDG. They have different vibes - Griffintown is very funky and is just now getting over the fact that it’s become expensive. NDG is an older neighbourhood with leaded windows in some houses and very close to Westmount, which has the highest taxes in the city and some drop-dead gorgeous mansions to drool over on your walk. Both have buses running through them and the walk to Villa Maria metro is not too taxing. In fact, I live close to Vendôme metro as well, so if I wanted to work at the MUHC, I could walk it.
The city is also working on its bike paths and there are bikes for hire called BIXI. Some Bixi have pedal assist, which is nice if you are going uphill, and my husband swears by them. Apparently on the Bixi app, you can see if there are pedal-assist bikes where you’ll be leaving from.
Unfortunately, I cannot give you any information about the other municipalities. My recommendation would be to live close to a metro station or, if possible, close to work.