I agree with spazzarama. The official resources are definitely a good, concise way to go if you're already familiar with programming in another OO language.
In addition, if you don't mind books, C# 4.0 in A Nutshell is a good book, and while the newest version of C# is C# 5.0 (with 6.0 coming soon), the concepts there are still relevant.
Besides C# 5 is basically just about async. Don't get me wrong, it's a critical new feature but
a) not really something a beginner needs to know
b) not really all that difficult anyways.
C#6 is pretty underwhelming from what I've seen and has some questionable additions ( jQuery style query operator??? ), but mostly it's fluff. Some of the new initialization options will allow for more terse code. In fact most of the new additions will allow for more compact code, which isn't always a good thing. Except the rise of a lot of "clever" ( read, intentionally obtuse ) code as a result. The biggest advantage is probably the open sourcing, meaning Mono will probably be the biggest beneficiary.