This is the guy who wrote the textbook I used to learn GR. The link is at the bottom of this post. It's not a popular introduction, it has real math and is a set of three individual hour-long lectures on introductory general relativity. It would help to know some basic calculus, calculus of variations, and some special relativity. Beyond that, if you don't quite catch the math itself you can always go through and watch the video to see how much you actually grasp...who knows, you might enjoy it.
It's not particularly rigorous.
http://www-conf.slac.stanford.edu/ssi/2005/lec_notes/Carroll/default.htm