Cisco are pretty heavy about the non disclosure agreement with reference to Cisco exams. They have a point. I don't want my Cisco certs to go the same way my MCSE did.
I can advise that the following books were a great help.
Managing Cisco Network Security
Cisco Secure Internet Security Solutions
Cisco IOS Network Security
And the new Cisco IDS book
I was also fortunate enough to have access to the CD courseware for PFA, IDS and VPN. These are pretty expensive but I see plenty of guys selling them on when they've finished with them (ebay/yahoo etc.)
The courseware was invaluable.
It never does any harm to cram a bit of your routing and switching library.
Good luck
