I should probably clarify why I've taken it twice, huh?
I've taken general chemistry twice - once for an AP credit (I got a 4 on the AP test, which is high enough to qualify for college credit but I rescinded the credits since chem is my major) and once (last year) at the college I'm currently at. Grade wise, I aced it both times and I feel really, really, ridiculously comfortable with it now.
I've helped people informally with chem many times over the last couple years and they have all said that I'm very helpful and even good at teaching. Once, when I was bored, I went on yahoo answers, made an account, and tried to answer all the gen chem questions I could up there. I didn't have trouble with any of them and I got ~75% best answer for the 30 or so that I replied to. I've also helped explain things to people that I know in real life over e-mail and on forums. I don't give them point-blank answers ever but everyone says I'm very helpful, so I know that I am at least somewhat competent at conveying what I know to them in a way that makes sense. They ask questions that show that they understand what I'm telling them too, so I know I help.