I am going to use this to clean up the html for some of the sites I maintain. The author (Omar Al Zabir, CTO of pageflakes) is one of the best .Net developers around.

Quoted: Convert HTML to XHTML while applying tag and attribute filters in order to produce nice and clean HTML for web posting.; Author: Omar Al Zabir; Section: C#; Chapter: Languages

Quoted: Whether you put your logic before or after calling base really depends on the scenario. Personally I always call base last, at the bottom of the method, just because in general I think it makes sense for my component/control to do its own 'X' before raising the 'X' event for external listeners to respond to. If I want to know about anything those external listeners have done to me, then I could have more code after calling base. But let me just say I can't really even think of a time where this should matter. If you end up with code that needs to worry about this, then just pause and consider your design, it's a CodeSmell. You should be able to design it in a manner that doesn't depend on such subtlety.

The problem with calling Validate in Page_Load is that your controls may not be ready to be validated (i.e. they need to be Loaded before they are ready to be validated).

Quoted: One potentially confusing thing about this timing is that the validators will not have been evaluated at the time Page_Load is triggered. The benefit of this is that it gives you a chance to programmatically change property values affecting the validity of the page, such as enabling or disabling certain validators.
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If this timing is not to your liking and you prefer to evaluate everything in Page_Load, you can do this by explicitly triggering the validation during this event by calling Page.Validate.

Some nice .Net "Cheat Sheets"

Quoted: The recent announcement that ASP.NET will soon get an alternate engine in the ASP.NET Model View Controller framework (MVC - see last month’s editorial) has brought out some renewed discussion of the merits and shortcomings of Web Forms and the potential need for an alternate mechanism of building...

You need to use an ASP:Button and not just an input if you want client-side validation in ASP.Net.

Quoted: The onclick attribute, along with the script, is added inside the AddAttributesToRender method of the Button control. The WebForm_DoPostBackWithOptions function can be examined in the rendered web resource JavaScript file within Visual Studio 2005, as explained in the above section. This function is in the resource file named WebForms.js. The function takes an argument of type WebForm_PostBackOptions. This function is also responsible for invoking the Page_ClientValidate function, which sets the value of the Page_IsValid member. The complete validation process triggered by the click of a button process can be summarized in the workflow below.

Great blog for truly understanding ASP.NET (if you need to and want to, of course).

Quoted: ASP.NET and .NET from a new perspective

This looks much more complete than Microsoft's official version.

Quoted: I've been playing with Facebook for a few days and am impressed. This post shares some thoughts as well as introduces a new open source project, Facebook.NET, a framework optimized for developing ASP.NET-based Facebook applications in C# or VB.NET.

Quoted: The following outlines the steps I took to create a new Facebook application written in ASP.NET using VS.NET 2005. I have not tested this in VS.NET 2003 so your mileage may vary there.