Add me to the list of newbies saying I want to liveaboard. I have been thinking seriously about it for over a year, and in the last 4-6 months I have been doing much more detailed research. I hope to be living on a boat soon but I so far have done a lot of hoping and it hasn't happened yet. Luckily I have a friend that has a sailboat (although not a liveaboard) for some advice, and even better is I have recently met someone living on their boat that has been Extremely Valuable for the advice they have been giving me.
I had been concentrating my efforts on boats that were 35' and larger since that was about as short as I could find that didn't seem too cramped. He mentioned a Morgan 33' Out Island and I have recently checked out a few of those and been pleasantly surprised by the spaciousness.
Moral of the story, if you can find someone doing it already, get as much advice from them as you can, its a great resource! These and other online forums have proven awesome as well so read as much as you can too, there is a TON of advice to be had. (of course always take it with a grain of salt)