As Grulstmrnn says, there is a bit too much ambiguity in your question to give you a good answer. In an attempt to be helpful, I assume that you are looking to code C# with one of the trading tools out there, so most likely C# Framework. I further assume, that you can already code reasonably well, and just need to figure out the specifics of C#. I personally like this book: It is a reference, which means: the focus is more on answering specific questions, rather than on teaching. Hope this helps, cheers Felix