Or instead of finishing of my code, you can do this tutorial. 🙂
http://robouk.mchost.com/tuts/tutorial.php?tutorial=login
It covers the registration and the logging in.
As for the account info, they can only see their own?
In that case, check if they are logged in, if they are, search the database for their username, and then the other fields should have data that's different for each user... Get that, and shove it in variables or an array.
Next, have one php script, called account.php for example, and create the layout and text.
Use phpMyAdmin to modify the database table, and the info of each user.
In the account page (I've never played Ultima Online... I meant to, but never got it lol. 🙁 ), just display the vars when needed... For example...
Welcome <? $username ?>, <br>
your current balance is: <a href="http://www.yoursite.com/bank.php"><? $money ?></a>.
Good luck.
EDIT: By the way, use a session to check if the user is logged in, so he/she doesn't have to login for every page...