If you are one of the editors who is waiting for the release after the dot zero of FCP X, here are the manuals on line.
However if you are thinking of installing it here are a few kb entries you should read before you do;
Installation best practices are discussed here
It would be nice to have a list of machines that do work with FCP X but for now here are the ones that won’t
Codecs will be important; so run Software update immediately you have installed
If you are using Sony camera data then after you have done the codecs, read this
Be careful if you have two cards in your system to allow you to drive two DVI monitors
When they get around to it you could read the release notes
Meanwhile you can find the whole of the help for FCP X here – there is a little printer icon top right if you want to save it as a pdf
If you are an AJA user then you need to read this; LHe and LSe owners need not apply for now.
There is a 142 page epub for your iPad or Kindle here written by the nice Steve Martin (not that one).
If after all that you get the urge to tell Apple well done! then here is the place to do it