If you are having particular problems, forums and google is good, but "The missing manual" books seem to be really good. Also do a search within the forum because there have been threads posted with books that are recommended. I have a few of the "Visually Learn" books.
Mostly I didn't need them much and the biggest problem with Mac is getting past the PC way of thinking. For that reason alone, can be the only reason for manuals for a Mac... If you never bothered with a diff OS, it's quite possible that learning to use a mac would be a lot easier - so perhaps just 'doing' as opposed to looking for equivalents or comparisons would make things go a lot smoother... Yes the programs might be complicated (and that also allows for the need/want for a manual) but it is/was the same with PC which I learned intuitively and quickly. My biggest prob with the Mac is that I like my games and so I still have my PC and therefore it is still 'easier' <- I use that word loosely ;D, to sit at my PC and do things that I could be doing more efficiently with my mac (I'm so ashamed hehe).