When it was announced XNA was going the way of the dodo, I looked into alternate easy ways to learn C# or other languages for use with Unity, but never really had much luck or much willpower behind it, as there wasn't much structure.
Then, a friend recently told me about this: http://www.coursera.org/course/gameprogramming
It's actually given by a teacher from University of Colorado, and if you take the course while it is live (it just started this week), you can apparently even get actual college credit for it as long as you complete it within time. The course goes over programming games with C# in XNA and MonoGame. While XNA is dead, MonoGame is an open platform that has XNA APIs, and can even export to next gen consoles, apparently. I'm pretty sure you'll also be able to use the C# knowledge gained within Unity, if you want.
The intro info so far as has been ultra helpful, and the course states that no previous coding knowledge is required, so I wanted to make some of my fellow duders aware.