It’s not straigthforward to find documentation in the Symantec web site about their products. Regarding to Backup Exec and VMWare vSphere there several documents spread in the site, even outside of it. Here it is a compilation of useful articles and documents.
Best practices for Backup Exec 2010 Agent for VMware Virtual Infrastructure
http://www.symantec.com/business/support/index?page=content&id=HOWTO21769&key=56792
Symantec Backup Exec 2010 Agent for VMware Virtual Infrastructure FAQ
http://webobjects.cdw.com/webobjects/media/pdf/symantec/Backup-Exec-2010-VMware-FAQ.pdf
VMware vStorage APIs for Data Protection (VADP) FAQ
http://www.symantec.com/business/support/index?page=content&id=TECH150567
How to backup ESX 4.0-5.0 using SAN Transport Mode with Backup Exec 2010
http://www.symantec.com/business/support/index?page=content&id=TECH155831
Known problems with SAN based backups and BE 2012 R3 SP1:
Slow throughput for SAN based AVVI backups of virtual machines post Backup Exec 2010 R3 Service Pack 1
http://www.symantec.com/business/support/index?page=content&id=TECH175944&key=56792
Deduplication methods for Backup Exec agents
http://www.symantec.com/business/support/index?page=content&id=HOWTO23358&key=58348
VMWare documents:
Best practices when using SAN transport for backup and restore
http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1035096
Administrator’s guides
Symantec Backup Exec 2012 Administrator’s Guide
http://www.symantec.com/business/support/index?page=content&id=DOC5211&key=15047
Symantec Backup Exec 2010 R2/R3 Administrator’s Guide
http://www.symantec.com/business/support/index?page=content&id=DOC2211
Landing page of Backup Exec Agent for VMWare Virtual Infrastructure
http://www.symantec.com/business/support/index?page=landing&key=56792
Video from Symantec Connect:
Protecting Virtual Environments with Backup Exec 2012
http://www.symantec.com/connect/videos/protecting-virtual-environments-backup-exec-2012