Very easy to get to with nice views of the city. There are a few ways to get there -- if you have your own car you can drive to the parking lot that is on Chemin Remembrance. You could be adventurous and bike up this same road to the top but that is a major climb. You can also hike fairly easily to the top -- we went through the Cemetery from the North Entrance as we were staying behind Mont Royal in Outremont. The initial part of this path was a bit steep but nothing too intense for an average person.
For some reason I kind of expected a grassy area where you could relax and even have a picnic if you wanted at the top but it is not like that at all. There is a strange cottage building (the Chalet) that looks like a train station inside but had nothing except access to bathrooms and a small gift shop (with some cool shirts actually). Otherwise it is just a bunch of different walking trails and then the main attraction is the big open square area for viewing the city with some steps that you can sit on.
Make sure you get to the chalet though! There is a small stop area off the road that has views of the city before you walk to the top and I wonder if some people think that is THE view -- it is not.
You can also continue walking further up to the cross (Croix) but don't expect much when you get there.
Anyway, overall it's a must-see in Montreal in my opinion but also a nice way to start your morning with some activity!