I think puppy classes are as much about training the trainer as training the pup. For the experienced owner there is probably limited need.
I have a new pup of nearly 7 months now - she has previously had no training. I was a bit dismayed when I found out our local trainer didn't take pups beyond 6 months, and to be honest I felt a bit panicky about doing this alone. However, with the help of a couple of friends, a minuscule amount of previous experience and the availability of info on CoL and T'internet, I'm sort of getting there. (I have however booked at a separate dog club for recall training).
As 8 Hairy feet says, the dogs trust vids are good and will assist you if you're a beginner. They're also available on youtube, et viola ...
http://www.youtube.com/playlist?list=PL4F64C87E574309A0Each command is talked through and there is a video (albeit condensed and perfect) of the act being performed.
These commands are in essence what you would learn whilst in puppy classes. Of course there is always the aspect of meeting other peeps and their pups which occurs when at classes but as you're getting out and about and meeting others and their dogs regularly I think that should offset the social aspect.
FWIW I think it's just a question of confidence. To try and test the theory try selecting just one vid and run through the lesson with your pup a few times - I feel pretty confident that you'll start seeing results fairly soon.
Good luck with it