Do SQL Queries Towards An SQL 2005 Express Server And Format The Return Value To JSON?

I'm completely new to both VB.NET and JSON, and I'm trying to figure out how to do SQL queries towards an SQL 2005 Express server and format the return value to JSON. I got the queries working using this (perhaps very newbie-like) code;

Imports System
Imports System.Data
Imports System.Data.SqlClient
Imports System.Web.UI
Imports System.Web.UI.WebControls
Partial Public Class SQLConnect
Inherits System.Web.UI.Page
'Defines SQL variables
Dim con As New SqlConnection
Dim cmd As New SqlCommand
Dim dr As SqlDataReader
Dim ReadData As String
Dim i As Integer
Sub Click(ByVal s As Object, ByVal e As EventArgs)
'Define SQL address, database, username and password
con.ConnectionString = "Data Source=localhostSQLEXPRESS;Initial Catalog=tempdb;User ID=tesst;Password=test"
Try
'Initialize connection
con.Open()
'Specify SQL query
cmd = New SqlCommand("SELECT * FROM Member", con)
'Execute query, dump result array into variable
dr = cmd.ExecuteReader()
messageLabel.Text = "<br />Connection established<br />"
While (dr.Read)
i = 0
For i = 0 To dr.FieldCount - 1
'Dump query results into a variable
ReadData += dr.Item(i).ToString
Next
End While
'Print query results
messageLabel2.Text = ReadData
'Close connection
con.Close()
Catch ex As Exception
messageLabel.Text = "<br />Connection failed<br />"
End Try
End Sub
End Class

I have been looking at this, and I would love to see some code examples using this class or any other good method.