I would really like a good reference with all the functions and examples for Unity development in C#. The online reference is very good, but it's mostly for javascript and I have to guess how to translate a lot of things.
I would prefer something online and free, but I would be will to pay for a book if that was the best way.
http://8bitfeed.com/2009/09/c-unity-3d-resources/ Has a few links.
The documentation does have some c#, but it's not consistent, as far as I can tell. Mainly, you want to become comfortable with C# language in general, read about how to convert from Javascript to C#, and then you'll start to be able to use the scripting docs regardless what language you're using.
I also found that setting up code completion in Visual Studio (PC only) is EXTREMELY useful (you do this by adding the UnityEngine.dll to you're project references). That's how I filled in a lot of gaps from the c# documentation. Maybe Mono can do that on a mac?
If you're in to video tutorials there are a few other resources.
also the new scripting docs for Unity 3 (I know not currently publicly available, nor finalised) have a choice for what language you want the examples to be in.. this is a great improvement and i can only assume will replace the online scripting API once Unity 3 is out of beta..