Honda motors

Hey, well im not exactly new to this site, ive been around for a few months, but dont post often. It seems that there are a lot of newcomers that have questions about all the different series of engines honda has out there. I was wondering if someone could either link me to a good site where the different series are explained a little bit, or if anyone could just respond with a little information, to me it seems like they're are like 20 different motors out there? Anyone else new feel this way?
Thanks,
Nick