I'm a technical person myself and working with my partners on an idea in healthcare. I'd be happy to meet up to chat. Email me dathoang [at] gmail [dot] com.
Learn timeless stuff in computer science that never gets old:
1. Learn C and master pointer arithmetic. All modern computers are von Neumann machines and this is the only way to learn how a real computer works and how OS is implemented. This is the low-end of the power spectrum.
2. Learn Lisp (Common Lisp, Scheme or Clojure) and master closure and macro. This will help you understand lambda calculus. This is the high-end of the power spectrum. You will learn things you didn't think were possible.
3. Learn the good esoteric languages in between:
Python - great for prototyping, web dev
Perl - great for Unix system admin
Ruby - great for web dev
Erlang - for concurrency
Haskell - for purely functional programming perspective
<any other language that interests you>
This will give you different perspectives on how to solve your problems. No one language is suitable for all tasks.
4. Learn to run Unix (Linux, FreeBSD, etc.). Start with an easy newbie distro then move on to advanced do-it-yourself distros like Arch, Gentoo, and FreeBSD to hone your skills.
5. Learn the Unix tools (grep, sed, awk, tr, etc.) and its editors (emacs, vi[m]).
6. Master sorting algorithms (quick sort, merge sort, heap sort, etc.) and their respective strengths/weaknesses.
7. Master data structures (heap, hash table, tree, list, vector, stack, [de]queue etc.) and their strengths/weaknesses.
8. Master graph theory and graph algorithms (shortest path, DFS, BFS, strongly connected components, etc.)
9. Understand TCP/IP (and other protocols), pipe, socket, IO file handling
10. Read source code written by top programmers. (FreeBSD/Plan 9 kernel and utilities, C Programming Language by K&R, PAIP by Peter Norvig, On Lisp by PG)
11. Work on interesting problems and challenge yourself.
Expect to spend the next 10 years developing your skills. You're only 20 so you'll be there by 30 ;-). Develop passion and curiosity for what you do.
Embrace a life-long learning attitude and help those who are less knowledgeable and be humble about what you know. And the most important of all: have good taste.
I wish you the best!
