A lot of the RPers use MyRoleplay or a version of FlagRSP. TotalRP is another, but I personally think it has a few too many bells and whistles added into it, particularly for a beginner. Most of them "talk" to one another (there's one version of Flag that still doesn't, I think) so there's no need to have more than one installed.
They let you add a basic character description beyond what the limited models show, and a basic summary/overview/publicly known/rumors character history. Mileage may vary on how much to put into the addon itself, but I personally think less is more, and link people to my Haven profile if they are really that interested in more details--9 times out of 10, they aren't; RPers are inherently more interested in their own characters, and find out about friends' through RP and discussion, in my experiences. Maybe story posts if they like the player/character/writing style.
Also, if you have to scroll through a huge RSP, some folks are turned off by that. "Let 'em find out most of it through RP and use the RSP as hints" is a popular theory. Either way, I recommend keeping a simple text file backup of your RSPs, short or long.
Chatloggers like Elephant or WoWScribe (originally created by ShC's own Scartaris) are helpful as well. MogIt, AtlasLoot, and CloseUp (a simple dressing room mod) help for finding RP/transmog gear.
Alliance side, we don't have a lot of open random walk up RP. Friday evenings is Wendy's Open Air Bar in the Mage District at 7pm server, and I know of 2 RP guilds with weekly IC guild meetings; The Silver Dragoons in the Stormwind Keep petitioner chamber on Wednesdays at 7pm server, and The Meddlers at Aerie Peak on Thursdays at 7pm server time.
There were other guilds with IC meetings, but they may be on hiatus or defunct at the moment, or just aren't advertising.
Other events happen now and then, and are usually advertised on Haven, though I know folks try to maintain the sticky posts on this forum as well. Olivia's Pond seems to be the place where most of our random walk-up RP can be found, and it's not unusual to find Dragoons hanging around the Keep garden, though a lot of us are on break/busy right now.
Some RPers use the /Haven chat channels, both Alliance and Horde, even if they don't use the website.
Our Goldshire seems mostly about dueling, but I haven't spent a lot of time there lately for anything. It's those other servers with Goldshire issues ;)
Edited by Alynore on 6/15/2012 12:17 PM PDT