FORTRAN is generally regarded as being the 'scientific' programming language. However; probably not for you yet as you're not a professional.
I'd advice you to start with Python as it's probably the easiest programming language to get started with and it's actually quite useful.
C, however, is...
Excellent. Thank you both! I'll definitely take a look at those lectures.
I didn't know prof. Crowell was a member here. Not only a member, but a very contributing member as well. He seems like a really cool guy, releasing textbooks in a Creative Commons license and all.
Physicist Benjamin Crowell has released several open-source textbooks on physics and mathematics; one of them being http://lightandmatter.com/area1sn.html" .
I have decided to study physics on my own in my spare time and Simple Nature seems to be quite sufficient; at least as an introductory...