So, should I join a class?

Short answer: yes!

I've had several experiences of learning a variety of languages, and I have generally found that one can make a certain amount of progress with a book and CD or CD-ROM at home. Indeed, I would encourage you to do just that before joining your class - it can be quite encouraging if you already know a bunch of stuff to impress everyone with!

BUT the point always seems to come - usually around chapter eight - where you simply have more questions building up that you can find answers in the book. Your questions will depend on your previous experience and the way your own brain works, so no book can possibly cater for everyone's (possibly anyone's) needs. You need to have someone to ask, and unless you have a fluent Spanish friend that you can pester for explanations, the easiest way is to join a class.

Even if you do have a fluent speaker to ask, I have often found that natives (of any language - not just Spaniards) aren't always the best people at explaining their own language. Someone who has learned the hard way may well have a better understanding of your difficulties and be able to give better explanations. Not all nightclass teachers are necessarily qualified teachers (though they generally are) but that doesn't mean they aren't good teachers. And even a bad or boring teacher, as long as they can answer your questions, will be better than getting frustrated and giving up at home. You can always find a different teacher next term.

Meeting up regularly with other learners will help with your motivation. You will also need the opportunity to practise speaking and receive feedback on your pronunciation; you can't really do that at home.

Happily, Spanish is pretty popular everywhere, so you should be able to find a class near you without too much difficulty. Ask in local schools and libraries. If one doesn't exist, you can probably find a teacher and start one! If all else fails, the internet can put you in touch with tutors who will explain things by email and give lessons over the telephone! If I get a chance, I'll list some links here.