Jen and Jeremy (and Jim) return with the latest Support Voice column. (no, it's not a requirement that all people in PSS have names starting with a 'J'). This month, Jeremy looks at tools to help you Troubleshoot ASP.NET. I'll definitely second the recommendation for Fiddler (and the SysInternals Tools). It's saved me more time and effort, I can't count. (I'd also add Firefox with the Web Developer extension. While it wouldn't help with IE compatibility, it's invaluable for doing CSS work or other "straight HTML" stuff).
In addition, they've created a new Support page for ASP.NET, and I *love* it. From one page, you can see great How-to articles, latest Downloads and more. (now, if we can just get them to release RSS feeds for all of them ;)