Sure, DAAB Data Access Application Block has lots of fans out there for providing helper classes and methods for connecting to Sql server.
When it comes to other data sources like Access, Oracle I had to search for a similar one :(
Luckily I found this in the new version of DAAB (3.1)
It has lots of examples and includes a document to extend and build your own helper class for any data source provided you have the appropriate .net classes for the same.

Microsoft Patterns & Practices Data Access for .NET: Home