I didn't take a class, but it was generally covered in our birth class.
I kind of wish I had, but I don't think any class was going to really help much with the six weeks of pain I had -- DD was latching correctly and everything, it just hurt.
But I highly recommend lining up a LC prior to birth or ASAP after, for an appointment during the first week. If I'd known what I know now, I would've called during the early stage of my induction (while watching movies with DH :)) and tried to get an appointment with someone on day 3 or 4, which was when the pain really started to get awful and I needed a lot of support and reassurance. But by the time I called, it took a week to get in an actually see someone. Luckily, we saw my pedi several times in that period and she was really supportive and as helpful as she could be, and the Nursing Mother's Companion was a lifesaver in the meantime.
Personally, I'd skip the class and save the money to help pay for the LC. The individual help when the baby actually arrived -- help with our specific issues, and just someone to talk to who really understood -- was what helped me get through.