Many years ago, I started with K&R's The C Programming Language, doing each example problem as I went. It took me about a week. Then I moved on to a VB6 book written for use a textbox for a Programming 101 course. (Wish I could tell you the name but I lent it out and never got it back.) After that, I was working full-time as an entry-level coder.
So I would say that the best thing is to find a resource, either a book (my preference) or a site, that is organized as intro-level material, starts at the very beginning and has exercises to force one to apply what one is learning, starting with the basics and building incrementally. I don't know of any sites that seem good for this, which is what your question really is asking for, but I'd say there are some very good books out there.
For C#, I am partial to Mark Michaelis's Essential C# book.