To build the DAL layer I decided to use the new DataSet Designer that is built-into Visual Web Developer (which you can download for free) as well as VS 2005, and which provides an easy way to create and encapsulate data access components within an application. I’ve used it for a few samples lately, and have found it pretty useful and flexible. I really like the fact that it enables me to avoid having to write tedious data access code, while still preserving full control over my SQL data logic (I also like the fact that it enables me to use both standard SQL statements as well as SPROCs).
Read Building a DAL using Strongly Typed TableAdapters and DataTables in VS 2005 and ASP.NET 2.0
Note: This is an old post moved from my Google page.