I write C# professionally in my "day job". It's not a bad language to learn if you're just starting out with programming. It's not something that you'll pick up overnight, but if your cofounder is interested in mentoring you, that's the best way to learn. DO NOT under any circumstances bother with any Microsoft certification course training materials. They're utter garbage. I learned from Troelsen's Pro C# and the .NET Platform:
Then again, I was coming from a programming background, so YMMV. I would probably try going to the bookstore and flipping through some of the .NET books, and deciding which one feels like it's a good fit.
Before you take the leap to learn .NET, though, make sure your cofounder is on board. You'll need his/her help and support.
http://www.amazon.com/Pro-2008-NET-Platform-Fourth/dp/159059...
Then again, I was coming from a programming background, so YMMV. I would probably try going to the bookstore and flipping through some of the .NET books, and deciding which one feels like it's a good fit.
Before you take the leap to learn .NET, though, make sure your cofounder is on board. You'll need his/her help and support.