Programming in Practice

Im a freshman in college right now, learning C in Computer Science.

What I was mostly wondering was, how does programming work in practice? How much do you really need to know by the time you graduate from college (I plan on getting my MS, btw), and what should I spend my time learning now in my spare time outside of class?

>>13
>>14

Then, what should I be looking to do outside of college, "above and beyond" the courses that I'm taking? I already plan on looking for internships every summer to get work experience. Still, what can I do exactly that will help me on my way to becoming a quote-unquote "expert programmer"?