Welcome to the boards. As Rivka said, how you post is up to you. Some people post as they go, others wait until they are done. It's usually best to have some sort of buffer so that if you get behind one week you can still post on time. Keeping a regular posting schedule will help you keep readers. You can set the interval - some people post every other day, some once per week, etc. Just be consistant. (If you do get behind, we'll forgive you. <G> This is just a good rule of thumb.)
As for a BR, this is definitely the place to ask. You probably want to give us some idea of what your story will be about since people have vastly different interests. You don't need to get indepth or give us an outline, something simple like "A short romantic story set in season two" or "an epic drama that deals with Clark's near death after he and Lois are married" will give potential BRs a better understanding of what you are looking for.
Good luck!
Annie
