Release Notes for SEP 11.x reaching back to SEP 11 RU5 - PDF documents for download.
The fix notes are based on the Article: http://www.symantec.com/docs/TECH103087 - here split into .pdf documents separate for each SEP Revision. Easy to find, easy to browse.
Additionaly some of the Best Practices, Installation-Client-Administration Guides for 11.x - as found on the Installation media from SEP 11 RU6 till RU7 MP3 - documents are in version 11.00.06.00.00.
I will try to add some more documentation in the future as well keep it up to date with next SEP 11.x Releases.