http://www.csharp-station.com/Tutorials/AdoDotNet/Lesson01.aspx
Today I was looking for a good tutorial for using SQL parameters rather than build strings on the fly. We ran into STAKS 😉 of problems trying to convert different datatypes into a correct SQL string.
That said the linked tutorial provides a great intro to parameterised queries and doesnt try to get you to do more hoops than you need. (see Lesson 4 I think)