I joined a local PMI chapter and they offered a "self-help", "self-study" environment where we met one evening each week for 11 weeks (one week per study area). This focused my study efforts but did not add greatly to my knowledge.
I got most benefit from reading and re-reading and re-reading my Guide to the PMBOK. This added greatly to my knowledge.
I have quite a few years of experience and the knowledge from that was useful because I could see how the theory in the Guide to the PMBOK related to my actual experience.
I bought some books but found them slightly misleading. In the end, the ESI Practice Tests were useful ... but only partially so: when a question used the Guide to the PMBOK as a reference source then the question was a useful test, otherwise ... well, not particularly helpful to me.
