Concentrate on one technology, say datatables or datasets. Learn it, then move on to the next. Here are several books.
http://productsearch.barnesandnoble.com/search/results.aspx?WRD=ado%2Enet>Enough to get lost in the various ways to access data - ADO.Net , LINQ , Entities etc. I have picked up pieces here and there to the point that I am now very confused. This is one of the reasons that I really do not like Microsoft products with the exception of VFP. They introduce new technologies, but they are not complete and just about the time they make it truly workable the next 'great' thing is rolled out the door but again it is not quite complete... I could go on and on but I think you can see my point.
Craig Berntson
MCSD, Microsoft .Net MVP, Grape City Community Influencer