allowing a specific group to access specific content

Hello.

There may be an easy way to do this, but looking and searching wide and deep cannot find the solution, please help.

I have 2 bulletin boards running on my drupal installation. 1st bulletin board can be accessed by all registered users. The 2nd bulletin board should only be used by a specific group of people. The way the site is set up, I manually create user accounts.

the ideal solution would be to give some users access to the 2nd bulletin while creating their account. the 1st group only sees the 1st bulletin, and the 2nd group sees both.

Thanks in advance for the advise,
Anatoly.