Unsealed Letters Offer Glimpse of Salinger.

The letters, a total of 11, were written between 1951 and 1993, from one buddy, or ''Buddyroo,'' to another. In sharp and familiar prose, laced with humor and biting wit, the writer gives an intimate peek into his life and thoughts at precise moments in time. Read so many years later, they are filled with surprises. The recipient of the letters was E. Michael Mitchell, a Westport, Conn., commercial artist who had designed the book jacket for a best-selling novel. [ABSTRACT FROM PUBLISHER]