If I want to develop algorithms or computer programs for studying chemical systems, where should I start? Is learning one or two programming languages like FORTRAN enough? And if I do it, then how do I proceed further? I would be grateful if someone can tell me about a book or any other learning resource.
Edit: I am 3rd year undergraduate in chemistry. I am interested in pursuing computational chemistry for my master's as well as PhD. I am mostly interested in electronic structure theory and ab initio calculations. Regarding the theory, I think I have got that part covered as I am taking courses and learning stuff on my own as well (QM, Linear Algebra, Quantum Chemistry etc.). What I want to know is the fields in computer science that I should have a knowledge of so that I can start learning it and be prepared with it if I encounter it in my grad school.