Recovery method depends on why the DB is suspect in the first place. There are a number of possible causes, with radically different solutions.
Please can you look through the error log and look for any messages that indicate why the DB has been marked suspect. Post those messages here.
Do you have a recent backup of this database?
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability