Do you have the server up and running at all or have you not messed with the configuration files yet?
As far as adding accounts, any user that has a regular user account on your system will have access via FTP unless you specifically block them. There is a file clled "ftpusers" in /etc/ . Any user that you add to that list will not have access to the system by FTP. If you dont want to allow annonymous access, just add FTP to that list because FTP is the annonymous user.
By default, when a user logs in they will be taken to their home directory. I use FTP on a server that I host a couple websits on. The way I do it is to add a user by the name of whatever the site is. Like user site1.com, then when user site1.com logs in he can add or delete files from his site. You can also set a default directory for all users that log in to go to a single directory rather than their home directorys if you need it like that instead. I am by no means an expert, but I have been playing with this around the clock for the last several days and I think I got it pretty nailed down.