One of the first things I like to setup when I am creating a new site is a customized error page and error logging. To log all unhandled errors on your site you can add some code to the Application_Error event of your Global.asax file. What I do is to grab the exception and then I use a static method of a helper class I have in my class library. I pass the name of the web application where the error occurred and the exception itself. In the helper method I can then extract the details I need from the exception and log it to a database table.
public const string APP_NAME = "Name of My App";
void Application_Error(object sender, EventArgs e)
Exception ex = Server.GetLastError().GetBaseException();
Next, in the web.config you can setup your site so the user sees a nice, customized error page instead of the default ASP.NET error page. Under the <system.web> node, add the following:
<customErrors mode="RemoteOnly" defaultRedirect="ErrorPage.aspx"></customErrors>
Now when your site is hit from a remote client (RemoteOnly) and an unhandled error occurs they will be redirected to the page you created (ErrorPage.aspx). This is much nicer for the user of your site.