Books are an easy and convenient way to learn. As I've recommended in other posts, Henry Horenstein's "Black & White Photography: A Basic Manual" is a great book to get you started. It's easy to understand, and you can follow it up with his book "Beyond Basic Photography: A Technical Manual". And of course, once you feel ready to dive into the deep end be sure to read Ansel Adams "The Camera", "The Negative", and "The Print".
What you will get out of a class will depend mostly on two things: the teacher and the equipment/facilities. If you get a good teacher and good facilities then you'll learn a lot. On the other hand, a questionable teacher and lousy equipment will probably be discouraging. Ask questions about the class when you are signing up. See if you can talk to the instructor. Check out the darkroom you'll be using, etc....
The fastest and best way to learn though is to just get into the darkroom and start doing it. Basic darkroom skills are not hard to learn on your own. You will become more comfortable and confident as you gain experience. Keep it simple at first, once you are familar with the basics, you can move onto more difficult concepts and techniques.
If you know that you are serious about continuing to use film, and you have the space and money for a darkroom, then I say go for it. Folks on this forum can give you equipment recommendations, and darkroom stuff is going cheap theses days. I guy I work with just picked up a complete darkroom set up capable of 35mm and MF work for $400(US). I do all I can to support "public" darkrooms (at community centers, art centers, schools, etc...), but my experience is that they are often messy (fixer dripped all over the place, yikes!!!) and the equipment is worn out. Not all are like that, but a rickety enlarger and chemistry contamination can really hinder learning.
Anyway, however you do it, whether through a class or on your own, just get into the darkroom and DO IT!!