Hello,
1.What Is being backed up can be checked in the selection list being used in the job propersties. and what has been backed up can be seen by what can be restores from the backup.
2. To include or exclude specific file types refer the following technote:
Title : How to add multiple file types to be excluded from a backup job
http://support.veritas.com/docs/237495
"NOTE : If we do not receive your intimation within two business days,
this post would be 'assumed answered' and archived."