So you have the basic gist of it, which is good. I like the way you put it as intuitive, because in my opinion writing/roleplaying is an art. You can teach someone how to write, grammar and all that whatnot, but the writer has to have a feel for the story they're writing. Philosophy aside, I'll give you a short run down on the way things are done(at least by me anyway).
Yes, it's a post-by-post set up. I post, then you post... Simple enough when it's two people. It varies for a group. Some groups will determine a posting order, and others it'll be more like a free for all(don't worry there is a warning that will let you know if someone has posted while you were writing).
OOC threads are more common for groups where as private messages, or PMs as they're called, are better for 1x1 RPs. Collaboration is key, it's not just a posting machine. Plots should be discussed and shared with the group, ideas and suggestions should be welcome as well. Planning and communication outside of the roleplay is as important as the posts themselves.
Character sheets are a big help for all parties included in a roleplay. It helps focus the thoughts of the creator as well as give a visual or reference for the other players. Simple CS's are alright but many look for more elaborate ones as a reference to the writing ability of the applicant(as some like a specific level of writer for their games).
Other things that are important to know are the basic rules of Elliquiy. Learn those, love those, live those. As long as you follow the basic rules of the site, you will do fine. On RPs you might find more specific rules for character creation or situations allowed for the RP. Read those before applying to play, and as long as you follow them you will do alright with the other players.
Most of the people I have met are very welcoming and friendly, willing to give a hand, forgive mistakes, help you grow kind of people. It's a wonderful community that I hope you will get to be a full member of. If there's something you don't understand, ask anyone of them(in the appropriate thread) and they will be more than happy to help you with what you need.
I'm sure there is plenty more to talk about, but they're all things you can learn as you go. Terms and whatnot. As of right now I can't PM you because you are not an accepted member, but upon your acceptance(which I hope happens) I'll be able to talk to you through those.
Anything I may have missed you can look up here
. Hope this didn't confuse you much.
With that out of the way I guess we can jump into RP planning. What do you say? Ready to get this started?
You're looking for the adventurous life right? Time for plot suggestions, I can come up with some for you to choose from, or if you had some ideas of your own, please share! Give me a few minutes for dinner and I'll pop back with some ideas for you.