my search criteria was 35-42 feet, blue water capable, strong, proven old boat, $30k - $80k. It took me a few months of looking at boats online to get an idea of what I wanted. So many variables and unknowns and I hadn't even sailed seriously.
my training was a weekend sailing course in the NY harbour. After that, much reading... internet, books. There's a ton of info out there and you realize it's pretty doable.
after I finished working and could finally go and buy a boat, I knew exactly what I wanted. Bought the first boat I saw in person, after drooling for it for months and hoping nobody snatched it. She is a beauty and has treated me well these past few months jumping around the caribbean.
all in all it's a pretty good deal. For the price of a boat I get a home with the world as my backyard. I can't imagine living any other way at this point.
Currently at a marina in Bonaire, close to Venezuela, connected to power/internet to do a remote contract. It's pretty sweet to go freediving or scuba diving a few feet away, then go to the "office" and work my ass off. Afterwards I'll be free again, sailing around for another bunch of months.
Challenges, well the obvious... getting distracted with the outdoors, oh man there is so much to do out there. But the pros are totally worth it and you strive to work hard to keep the lifestyle. If you really want it, everything will work out.