>Provide me some information abt RMAN.
what kind of informatioN are u looking into? everything is in documentation.
>How to implement RMAN?
u can implement RMAN backup with or without a catalog.
Oracle strongly recomends to use catalog so as to make use of all features of RMAN.
create a password file for the target database.
Establish tnsconectivity between target and catalog dadtabase.
Backup/ restore target database using RMAN scripts.
 
>Minimum requirement for RMAN?
though implemented with oracle 8.0 , a stable version is available with 8i. and it very advanced and highly reliable with 8i and 9i
RMAN is distributed along with enterprise editon.
>What is the best use of RMAN?
u can backup/restore/clone databases POINT-IN-TIME.
target databases need not be in hotbackup mode..