All the better seminars will be held in the winter while the pros aren't fishing. Seminars are good but you can get just as much knowledge watching the television programs. I would check the tv guide and try to watch some bass fishing shows. Keep your eyes open for good seminars featuring big name fisherman during the off-season at boat shows and such.
I went to the Bassmaster University a few years back. I agree with "leeabu" that they are every bit worth the cost. I got the chance to chat with Woo Daves, Larry Nixon, David Fritz, Allton Jones and others. It was very enjoyable to see them poking fun at each other too.