In a salute to Older Americans Awareness Month, the Monroe College Department of Continuing Education is running a series of computer classes for senior citizens.  On Friday, May 11, in the first of the two session course, a dozen seniors from the Northeast Bronx Senior Citizen Center and two from the New Rochelle Municipal Housing Authority learned basic computer and mouse operations, as they began their investigation of computer games and the Internet in a computer lab on the Monroe New Rochelle campus.  The sessions are being sponsored by Councilman Jimmy Vacca and the two senior citizen organizations.