Redhat manuals are pretty ok. Only realy usefull with Redhat/Fedora stuff.
If you pay for a distro, such as Redhat/Mandrake/Suse they will provide printed documentation and online/phone support.. depending on pricing options of course.
In my sig I have linked to a website that has good guides. Check out the ones I have listed, in the order I have listed (pretty much, do what you think is best for you of course). Those are usefull irregardless what Linux distro you use, pretty much.
Picking which distro is a matter of personal choice.. they mostly support all the same hardware (because they all share the same or similar source code), but differ in default configurations, setups, and scripts which can make things more or less easier or harder.
I think Ubuntu is nice, mandrake, suse, fedora are nice ones too. Gentoo is ok. My personal favorite is Debian (ubuntu is based on Debian) and I like slackware (no frills, no hand-holding style)
If you prefer killling trees you can find lots of books from any larger bookstore. They often have a whole section dedicated to Linux and Unix stuff.. beginning books, programming books, stuff like that. Some even come with their own Linux install disks...
However! becarefull and always get the newest version of whatever distro you want to use. Newer ones have better hardware support, bugfixes and better functionality.
Also most distros have their own distro-specific forums you can go for help, as well as FAQ pages and online documentation as well as mailing lists and IRC channels.