An environment description (including Servers, Operating Systems, products with editions and fix packs installed and a brief on the clients and how the clients reach the servers, gateways if exist, an so on).
A database description – a list with all databases, including server and instance, if they are in production or development, the developer or people “owner” of the data in the database in order to contact in case of problems.
Backup and restore strategies, products used for this, scripts and so on
What jobs are run on the servers ? Their schedule, purpose, duration etc.
When Rebuild and Reorganize are done, is there a manual process or is programmed, and if programmed where and how.
Linked servers if any.
Daily checklist that is normally performed.
Usernames and passwords.
Brief on the applications using these servers.
Normal files sizes and maintenance tasks performed.
Common Issues – what kind of errors to expect.
What are the manual tasks he performs – Daily, Weekly, Monthly & Annually.