There should be a standard smartnet contract available for the SE - check with your reseller.
Regarding backup - if you need high availability then purchasing two SE's and configuring database replication between them would be your best bet. Otherwise just remember to do regular backups in case you ever need to do a system recovery.
Regarding training - I'm not aware of any ACS-specific training but some of the security courses do cover aspects of the ACS, but you'd have to check with your local training provider. However, there's an excellent primer at:
Table of ContentsIntroductionVersion HistoryPossible Future
UpdatesDocuments PurposeNAT Operation in ASA 8.3+ SectionsRule Types
Network Object NATTwice NAT / Manual NATRule Types used per SectionNAT
Types used with Twice NAT / Manual NAT and Network Obje...
Table of Contents Introduction:This document describes details on how
NAT-T works. Background: ESP encrypts all critical information,
encapsulating the entire inner TCP/UDP datagram within an ESP header.
ESP is an IP protocol in the same sense that TCP an...