App. design help

Hello, I need to write a php/mysql application for managing a website for a sportsclub. At his point I need some designin tips how to implement the user and team administration. At the moment the club consists of about 30 teams. There are usually 1-2 web admins per team to update the pages. The current -crappy- system now has 5 columns in the user database table and in these columns there are the team id's of the teams that the users has rights to. Like this: USER TM1 TM2 TM3 TM4 TM5 JohnW 7 6 12 3 Which gives JohnW access to team's (id) 7,6,12 and 3. Main problems with this system are that user access is limited to max 5 teams and that if you add a new team to club theres now way automatically assing admin for that team. Team id's come from the teams table. Both teams and users are now administered manually by modifying the DB tables. So how to write a system that is able to add/remove teams. And here I refer mainly to the DB desing (I figure out the code later). Can I put the team id to the column name in the users table and like X to the right field and add/remove columns when teams are added or removed. Can I write SQL queries that return column names that has an X in them where user=user to get the team id's that user has access to??? There must be some 'normal' way to do things like this. So please point me the way. Thanks -Will