How To Start A New Thread To Query A Database While Web Application Continues Running

I want to start a new thread to query a database while my web application continues running. I was under the impression that by using threads I can run the querying process independently while the normal web application page cycle carries on, but I could be wrong.

public class DbAsyncQuery
{
Dictionary<string, object> serviceResults = new Dictionary<string, object>();
public void UpdateBillingDB()
{
QueryAllServices();
foreach (KeyValuePair<string, object> p in serviceResults)
{
IEnumerable results = (IEnumerable)p.Value;
IEnumerable<object> sessions = results.Cast<object>();
DbUtil.MakeBillingDBEntry(sessions, p.Key);
}
}
public static string[] servicesToQuery = new string[] // Must go in config file ultimately
{
"xxx.x.xxx.xx"
};
public delegate void Worker();
private Thread worker;
public void InitializeThread(Worker wrk)
{
worker = new Thread(new ThreadStart(wrk));
worker.Start();
}
public void InitializeQuery()
{
Worker worker = QueryAllServices;
InitializeThread(worker);
}
private void QueryAllServices()
{
Dictionary<string, DateTime> lastEntries = DbUtil.GetLastEntries();
foreach (string ip in servicesToQuery)
{
string fullServicePath =
"http://" + ip + ":800/MyWebService.asmx";
//object[] lastEntry = new object[] { lastEntries[ip] };
object[] lastEntry = new object[] { new DateTime(2011, 1, 1, 0, 0, 0) };
object obj = WebServiceHandler.CallWebService
(fullServicePath, "MyWebService", "GetBillingDBEntries", lastEntry);
serviceResults.Add(ip, obj);
}
}
}

It seems to basically stall and wait to finish the query before loading the page (which can be thousands of rows, so it takes awhile). I put this in the following section of Global.asax:

protected void Application_Start(object sender, EventArgs e)
{
DbAsyncQuery query = new DbAsyncQuery();
query.UpdateBillingDB();
}

This is one of my first web pages, and I'm new to threading. I understand there is a difference between creating your own thread and using the ThreadPool. In this method, I am using my own thread, I think. Not sure if that's the best way. The querying process can be completely independent, and its only going to occur on scheduled intervals (every 8 hours or so). The user doesn't need to have up to the minute data, so it can take awhile. I just don't want the site to wait for it to finish, if that's possible.