As a reservist in Ontario, I feel pretty qualified to weigh in on this.
Probably nine soldiers out of ten will do their BMQ part time during the fall and winter, roughly every second weekend. They'll then do a BMQ(L) and DP1-Infantry that summer, either in June/July or July/August. Then they show up at their regiment and play new guy for most of a year.
Full time BMQs in summer have occasionally happened. I've never heard of part time summer BMQ; everyone who wants to do army work is tasked out full time, and the rest are doing whatever it is you do in the summer when you aren't grabbing your ankles for the army (Every summer since 2004 ;D).
If you can make that every odd weekend and that first two month summer, though, you're good, and moreover you start to become useful to us.
BMQ- How to dress yourself, shave, wake up early, and march up-and-down the square. Basic rifle handling. Suck in tear gas build character, and every possible iteration of the 'f' bomb.
BMQ(L)- More weapons (machineguns, grenades), basic fieldcraft, participating in a reconaissance patrol, participate in section attacks, and sit cold and getting rained on in a shoddily constructed trench for four days build character. NAvigating with map and compass, living in the woods... Some other stuff that I've no doubt I'm forgetting.
DP1- Inf More weapons (mortars, grenade launchers), platoon level tactics such as fighting patrols, hasty attacks, platoon defensive operations character building, and so on and so forth.
Any more questions, don't hesitate to ask. My knowledge of specific course curricula is two years behind, though; minor variations may have been made.