To you gridview add a button field column.
<asp:gridview xmlns:asp="#unknown">
<columns>
<asp:buttonfield buttontype="Link" text="Edit" commandname="Edit" />
</columns>
</asp:gridview>
In the code behind handle the row command event.
Private Sub gridview_RowCommand(sender As Object, e As GridViewCommandEventArgs) Handles gridview.RowCommand
If e.CommandName = "Edit" Then
Dim iRowIndex As Integer = CInt(e.CommandArgument.ToString())
Dim iId As Integer = CInt(grdParadeSignUps.DataKeys(CInt(iRowIndex)).Value)
Response.Redirect("EditRegistration.aspx?ID=" & iId)
End If
End Sub