I have a 5 yr old male that I show on occasion. both males and females are love bugs, though I have seen some females have issuses with other females(keep in mind that all of these were intact females). They are very smart and can be trained fairly easily. You'll need to be gentle with them and practice everyday when training. You have to keep an eye on them at all times, they could chase a butterfly into oncomming traffic if you let them, not to mention the countless bad guys out there who will steal them.
The most important thing you can do for your future pup is to accquire one from a reputible breeder. Since most cavaliers are practicaly concived with a genetic disease, it's importat that the breeder test for all of them that they can and only breeds the dogs that pass these test with flying colors. The breeder should know all of the dogs in the pedigree, How long they lived, what they passed away from, and if they had any genetic diseases. the breeder should be in good standing with the AKC and the cavalier club of the USA
http://www.ckcsc.org/. They should also compete with their dogs(conformation, obedience, agility, ect.). they should be breeding to better the breed, not to make cute family dogs (that usualy end up with a genetic disease by the time their 2). And having a guarentee against health problems doesn't mean much if they aren't willing to take the dog back at anytime for any reason.
I'm sure there's something that I missed and there's a ton more that I could cover. You can always PM if you have more questions regarding cavaliers. And here's a link to a cavalier specific forum
http://www.cavaliertalk.com/phpBB2/index.php