I've been taking pictures exclusively with Canon's nifty fifty ever since someone broke into my car and took my other two lenses. This means over two months now shooting everything with it (except a couple of pictures when someone borrowed me a different lens).
This made me try to push the lens to its limit. I found out it is indeed a good lens for portraits, but you should be very careful when using it at f/1.8 because of the very shallow DOF. It's not uncommon to focus the subject's nose and have the ears out of focus or something like that. You can even see that in shortpballer's post. That picture of the girl, here nose is focused but the hands are very slightly blurred. If he had gotten any closer, it would be even more noticeable (and I have no idea if those were shot at f/1.8).
I shoot mainly live bands and spot meter to the face. Because of the subject's movement, one very common mistake I end up making is having the microphone in focus and the face gets blurred.
Also, the lens is sharper at f/2.5 and lower apertures. Keep in mind that non-full frame bodies make it look more like an 80mm or so. It's not easy to get two people in the shot without them being very close together or you being a couple of yards back. I'm sure you'll get the hang of it in no time
EDIT: Shortpballer, you sure that's shake you're getting? Isn't it the extremely shallow DOF? Just asking because I very rarely get shaky pictures with it and I mainly shoot in dim light, no flash and no tripod. But I do have very steady hands. I actually won a bet because of my steady hands, by shooting with a 250mm lens at 1/15 and getting a steady shot

. I dind't even breathe when I took it, it was one in a thousand