What are some best practice approaches such as:
- SCD type 1/2/3
- nulls
- duplicates
- missing data
- extra data
- special characters
- FK/PK referential integrity.etc
I believe this article gives a good overview of the different data warehouse testing that should be applied: http://quality-gates.com/?p=1284 We are using this method in almost every data warehouse project.
I found this to be a useful, though high level article about data validation.
It's more about how to approach the testing than specific tests, but it does contain some specific tests and has a lot of useful information: http://msdn.microsoft.com/en-us/library/gg261774.aspx.