Hi Tapshoes!
Glad to see you're interested in taking that step just like the rest of us.
This thread will give the impression that my journey has been a long one, because I have been wanting to do this ever since I started my BSW, and have been posting in this thread just as long. I graduated with my MSW last May, and the only reason why I haven't left for the UK just yet is because the rules have tightened SO MUCH since I first began this journey. Pre-2008, newly-graduated Americans had the easy-as-pie BUNAC option for a work visa, and one could go on to get a two year work permit for pretty much any area of social work. Of course, I wasn't ready to go to the UK permanently at that time as I was still in the middle of my studies (I did spend a summer in the UK via BUNAC, just to ensure I'd like the place), and by the time I had my MSW and could register with the GSCC, UK immigration laws underwent their current make over.
As of right now, I'm doing thorough research on which area of the UK I'd like to live and work, and waiting for the results of my CRB (which is something that's needed, along with GSCC registration). I'll PM you more details.
In terms of "risk" in registering for recruitment agencies, I haven't had any problems so far. You should never, ever have to pay money to a recruitment agency. If an agency is asking you for money, then it's a con.
Also, check out all of mapleleafgirl's comments/links. She is an EXCELLENT source of information, and if she doesn't know the answer, by golly, she'll be sure to tell you who does. lol She's a peach, and a real asset to this board.