Question : What is Best Practice in Data Governance ?
Best Practice for Data Governance requires the successful completion of many Tasks, most of which are not technical and 
all of which are complex and challenging.

The process of initially establishing Data Governance will always take much longer than anticipated. 

Therefore, management of expectations is very important.

It is necessary to aim for collaboration and buy-in from the start.

This buy-in must be top-down and bottom-up.
The top-down buy-in manifests itself by, for example, a realization that ‘Data Quality is an Enterprise Issue’.
The bottom-up buy-in is important because quality of Source data is critical and must be good, otherwise any 
Data Governance issue will fail.

Auditing, for example, of database changes, is a basic requirement.

Here are some Useful Links
It's worth checking out Wikipedia on Data Governance

This 20-page PDF document describes the Framework from the Data Governance Institute.

The Data Governance Institute - Membership starts at $150 for individuals.
 
ii) The Data Governance and Stewardship Community of Practice - $150/year. 		-
It includes coverage of some very useful Case Studies.

It also maintains a Data Governance Software Web Site,
and a Sarbanes-Oxley Web Site.

This 20-page PDF document describes the Framework from the Data Governance Institute.