Where do you get the best in-depth information for C# programming? I'm looking for tutorials, examples, blogs, specialized forums etc. dedicated to c#.
Eric Lippert's blog is second to none, IMO.
Charlie Calvert's Community Blog is also good - especially the Community Convergence posts which highlight interesting posts from elsewhere.
I recommend you Jeffrey Richter's "CLR via C#" book. You can learn CLR features and how does c# implement them. Also you can learn a lot about multithreading in c#, localization, appdomains etc. .net topics.
Hidden Features of C# on StackOverflow:
http://stackoverflow.com/questions/9033/hidden-features-of-c
Jon was quite humble, but (in addition to Eric Lippert's blog he mentioned above) his writings are indispensable:
This applies more to the .NET programming in general than C# in particular, but Krzysztof Cwalina's blog and Framework Design Guidelines are excellent for deep understanding of .NET internals.
When I've got a first job as a software developer I spent some time to go through Wrox Press - Professional C# 2005 and shortly after that I started to look at the examples from codeproject and msdn. Now when dealing with some new thing I just try to break it into pieces and use google to search forums and of course stackoverflow and then put pieces together.
DotNetKicks is a good source for .NET related articles across the intarwebs.
And, if you need a limo in Surrey, keep an eye out for the spammer in Upcoming Stories.
For other languages I find it extremely useful to join IRC chats with other users of that language to receive extremely useful help. Sometimes it is not even a matter of if the answer is available- if you are not in the right frame of mind you may not be looking in hte right places. THe best option is to have other people to talk to that are also familiar with the language to speak with to help you understand from another developers words.
Besides 'live chat' you should use google to find descriptions or examples of what you are looking to do. If you need a larger overview of the core concepts, read a book. But if you are looking for fine grain detail I suggest googling on a per case basis. You can't expect to have all the in-depth knowledge without having in-depth experience which will come when you have a particular problem to solve.
Unfortunately I don't know of an active IRC channel for C# (Anyone know of one?!)
I found the WROX Professional C# [substitute latest version here] to be a good starting point to the C# language.
For advanced techniques, I highly recommend "More Effective C#" by Bill Wagner.
DevX.com is a great place to ask questions, and is one of the few programming forums where the moderators don't allow much in the way of picking on newbies. Each of the forum sections is moderated by someone with a measure of authority as well.