We took Bradley with our 1st, (ended with CS for FTP) and this time we are doing hypnobabies home study course. I think it's great, especially for a VBAC, and since you have two kids at home already, you can do it on your own time.
I'd take some kind of class, as the more info you get the better, ask your Doula if she can come with you. If not, take notes and go over them with her. I'd say the more you do to prepare, the less you can look back and say, "I should have...."