Well for me, i decided in grade 11 that i wanted engineering but i wasn't sure what stream i wanted to go to. I chose engineering because the only courses that i liked in gr 11 were math and physics; i didn't like chem and bio.
You gotta see what you like doing and go for it, for example if you like playing with wires and circuits you might wanna check out electrical engineering. If you like seeing construction sites and have a passion for how they build houses, you might wanna check out civil. That's how you get closer to deciding what you wanna do. From there, take a look at the courses that each program offers and see if they seem interesting.
Once you have an idea about engineering, take a look at the courses offered. That's how i chose mine
I looked at the courses and a lot of them seemed interesting.
Here you go:
http://registrar.mcmaster.ca /calen...13/pg1202.html
Just click on any stream and it will show you the courses offered.