Bear with me here -- I'm relatively new to cycling.

I ride a Trek 2.3 with a Shimano 105 triple. I've had folks tell me I need a compact crank, but I've also had folks tell me not to spin in too low a gear or it'll put unnecessary strain on my knees. I climb a fair amount of hills, but I've been told to just buy the compact and stand up to pedal on the tough inclines. Is this great advice or terrible advice? I'm only 23 and I'd like to keep the knees I have now until I'm at least 65.