NOTE:  If you are trying to JOIN a pool and were given a "Pool ID" and "Pool Password", you must still register to create your own, personal account.  After you login with your personal account, go to the Pool Tools menu, you'll click Join a Private Pool, select the pool type and that is where you'll enter the Pool ID and Pool Password given to you by the person who invited you in order to join their pool.

After you've joined a pool, you won't need the Pool ID and Pool Password anymore.  All pools you've joined will be listed on your "My Pools" page.  Click on the pool name there and you're back to that pool where you can make picks or view results!