I like this American site : http://www.cascity.com/index.shtml - see the forum.
The guy's on this site are very helpful and friendly, sections covering Colt and Remington bp's etc..
Bp pistols don't hold their value very well, so if I was you for your first pistol I'd go for a second hand pistol. If possible in stainless eg. a Pietta or Euroarms Remington 1858. The Colt clones point better than the aforementioned, however they are open topped and use a wedge to hold the barrel to the frame, if you have a misfire etc can be a bit troublesome to remove the wedge and cylinder to determine the problem. The Colt is the way to go when you are more familiar with the quirks of bp pistols.
Regarding powder if your a purist go down the avenue of obtaining a licence to hold the holy black. I can't comment on this as at the moment all I'm using is 777 and Pyrodex P.
If you can get some experience shooting your fellow club member's pistols, and when purchasing take someone who knows about revolvers with you.
Safe shootin..