You can park at the first lot at the base of the trailheads 1 & 2 or you can drive up to the observation tower and choose to hike a little from there. All three trails are well groomed, well marked, and have route maps posted at the beginning and midway points. #winning
Trail 1: From the main parking lot at the base of the mountain, you can hike up trail 1 and either a) opt to go straight to the observation tower if you hit the road after the switchbacks or b) you can continue on trail 1 and enjoy the extra kms along with the second lookout before going up the observation tower (recommended).
Trail 2: On our second trip to Mont Morissette we decided to park at the top parking lot, hike trail 1 and the hike the full length (4.5kms approx with 400m elevation) of trail 2. It was a moderately challenging hike, well marked, and we really enjoying being in the thick of the woods.
Although the observation tower is the obvious highlight of the hike during the fall months, there is also another second lookout along trail 1 which is equally breathtaking. Especially if you manage to get up there during sunrise or a foggy morning!