The following is a list of APIs and tools which I consider the current state of the art in .NET development (though not exclusively .NET) and that I really should know a lot more about. This should pretty much be complete right now, though I have a nagging feeling I missed one.
- OpenRasta
http://trac.caffeine-it.com/openrasta/wiki/Doc - ASP.NET MVC 2
http://www.asp.net/learn/mvc/
http://channel9.msdn.com/posts/matthijs/ASPNET-MVC-2-Ninja-Black-Belt-Tips-by-Scott-Hanselman/ - SparkView
http://sparkviewengine.com/documentation/syntax - Castle
http://www.castleproject.org/activerecord/documentation/v1rc1/index.html
http://gojko.net/2008/11/04/dependency-injection-with-castle-windsor-video/
http://using.castleproject.org/display/IoC/Home
http://using.castleproject.org/display/IoC/Fluent+Registration+API
http://www.castleproject.org/castle/download.html
http://api.castleproject.org/
http://blog.coreycoogan.com/2009/11/06/castle-windsor-tutorial-in-asp-net-mvc/ - NHibernate
http://nhforge.org/
http://community.jboss.org/wiki/NHibernateforNET
http://www.nhforge.org/doc/nh/en/index.html
http://blogs.hibernatingrhinos.com/nhibernate/archive/2008/04/01/your-first-nhibernate-based-application.aspx
http://www.ayende.com/hibernating-rhinos.aspx
http://nhforge.org/wikis/howtonh/your-first-nhibernate-based-application.aspx - MvcContrib
http://mvccontrib.codeplex.com/Wikipage
http://mvccontrib.codeplex.com/releases/view/43560 - NUnit
http://www.nunit.org/ - Ruby On Rails
http://ironruby.net/About - Fluent Programming
http://en.wikipedia.org/wiki/Fluent_interface - NerdDinner
http://nerddinnerbook.s3.amazonaws.com/Intro.htm
http://www.hanselman.com/blog/ExtendingNerdDinnerExploringDifferentDatabaseOptions.aspx
http://www.hanselman.com/blog/ExtendingNerdDinnerAddingMEFAndPluginsToASPNETMVC.aspx - Managed Extensibility Framework "MEF"
http://mef.codeplex.com/
http://code.msdn.microsoft.com/mef
http://blog.maartenballiauw.be/category/MEF.aspx
The following list is not complete, won't be for some time and may require time travel to keep reasonably accurate - list of best practice advice/docs:
And some videos which I hope will be helpful:
Footnote: This needs reorganising into a list of tech, each with a list of links and FAQ/Quickstarts.