Update or Insert SQL Server 2005 using VB.net

I'd like to update or insert a new record into a SQL Server 2005 database using VB.net.

Knowing that my values will contain single quotes, I'd prefer to update the fields within my tables using the individual field names rather than a blanket INSERT command.  

For example, in VB6, I could write something as follows to accomplish the above:
 
   sSql = "SELECT * FROM MyTable"
  objMyRst.Open sSql, cnn, adOpenKeyset, adLockOptimistic, adCmdText
   If objMyRst.EOF Then
      If objMyRst.State = 1 Then objMyRst.Close
      sSql = "MyTable"
      objMyRst.Open sSql, cnn, adOpenKeyset, adLockOptimistic, adCmdTable
      objMyRst.AddNew
   End If
   objMyRst!Testfield = Now()
   objMyRst.Update


Any help in performing both the insert and update would be appreciated.