Hello, been a while since I've came around

Searched and couldn't find anything. So lately I've been having to drive my roomates 1998 I30, and last night it wouldn't start. I turn the key, all lights come on, I hear a click below my left knee (I'm assuming it's coming from the fuse box), but the car does not turn over like there is no power going to the starter. I hear a small buzzing sound on top of the engine when I turn the key, but it's not coming from the starter. It did this to me last week as well, and after trying EVERYTHING I could think of (locking and unlocking the doors, moving the shifter, checking lights and all accessories, cleaning battery terminals, rolling the car back a little, jumper cables) to no avail, I stepped back and talked to some friends then tried it again and it started.
Now, my roomate and I have both had the problem where the key is really hard to turn, or just won't turn at all. I have to jiggle the hell out of it, take it out, repeat until it finally turns. Other times, it has no problem. My friend thinks it's the ignition switch causing the problem, I have no idea. Also right now the car is not here at home, I have to go to it later today to try and get it started, but i will answer any additional questions best I can.
Any ideas?