I have been investigating enterprise architecture for an application
like this...

    Presentation <-> Business logic <-> Data access <-> Database

My issue is mainly between the Business logic and Data access layers.

    1. I can have Visual Studio create strongly typed DataSets
    with the connection strings, select/update queries built in,
    and enforce logic with properties... all without writing any
code!

    2. Or, using a Data access class, I could stop the DataSet when
    moving up or down the layers and enforce the business rules there
    (check values, allow or deny updates, enforce min/max values).
    <http://weblogs.asp.net/rosherove/archive/2003/07/28/10607.aspx>

    3. Or, I can use the wizard-built DataSets, intercept the
TableAdapter
    class in another class, intercept the DataSets, and enforce
business
    rules there.
    <http://www.asp.net/learn/dataaccess/tutorial02cs.aspx?tabid=63>

And all 3 of these methods can be bound to controls and manage the db
connections properly.