Is possible to learn Solaris 10 from guides for Solaris 9
Then look for "whats new in SOLARIS 10"... I think sun has a free demo/tutorial for the new functionalities...
Most of what is in Solaris 9 will still be true for Solaris 10 with a few exceptions. What you will be missing is info on the new features of 10 like ZFS, Dtrace, etc.
Sun Microsystems Documentation is a great place to start. I recommend downloading their entire solaris 10 collection and start with the user's guides and then move on to the administration guides.