Backup Exec 12.5 - Advice with B2D

Hi all

I've inherited a 12.5 system, 5 servers all Win2003, everything backs up to a 6TB NAS so no tape.  Each backup is around 300GB.  I've never used BE before so a little lost with the terminology I just want to ensure I'm doing it right.

I basically want to allow the system to do daily incrementals with a full on Sunday and to use all the disk space, i.e. only start overwriting the backup once disk space has been reached.  Is that an ideal plan or is it better to put a time limit on the backups, i.e. 6 months

Would I just need to:

create a media set for 6 months
create a B2D folder
create the actual backup job

I'm a little lost on the append and overwrite settings....

Sorry very new to this.

Cheers