2. Stack Overflow
3. Khan Academy
6. Hacker News
7. No Excuse List
9. Memory Improvement Tips – How to Improve Your Memory
ps. I added explanations as per request in the comments.
1. GitHub – thousands of projects with their code, examples, etc. – invaluable for your projects, school, work or life as a software/CS engineer.
2. Stack Overflow - answers to thousands of questions on all kinds of topics related to programming, work, math, software, etc. (You can also answer, and it has Careers 2.0 (invitation only after you answer and gain points) similar to LinkedIn which you can leverage to find software/cs jobs).
3. Khan Academy – math, statistics, economics – everything you missed out on in college and high-school and wanted to re-learn, re-visit, etc.
4. tutorialspoint.com – has easy-to-follow tutorials on major topics in programming and cs concepts, which you can cover in hours and literally be an expert in amongst your peers.
5. TopCoder – MONEY, recommendations, algorithms, experience (I wish I knew about TopCoder while in College). There is rarely a website that can do so much for you as TopCoder can.
6. Hacker News – The only place you need to follow when it comes to latest news on technology, whats hot, whats cooking, etc. Thats the place where all other hackers come to get and post the news.
7. No Excuse List – This lists out all the major places on the web for courses, materials, and other stuff CS people need and basically empowers you to learn anything and everything you ever needed/wanted. You simply have no excuse anymore as to why you didn't know or learn something.
8. http://www.businessballs.com/ – Place to learn economics/buisness/job/work terminology and about starting your business, organizing your time, people skills, people management and utilizing your knowledge to finally start making money out of it. All sorts of tools and general knowledge which you will need at some point in your life. Everything you should know about business, management and stuff that no one teaches you at college, but you find out you really need to know later on in life when you want to create your own startup/business or as such.
9. Memory Improvement Tips – How to Improve Your Memory – website you need to learn about your brain and how to improve your focus, memory, etc – website I would use in combination with this book: Your Memory : How It Works and How to Improve It: Kenneth L. Higbee Ph.D.: 9781569246290: Amazon.com: Books – it teaches you how to memorize, what affects your memory, focus, etc. I wish I knew about these things in college. If you follow what is taught in this – you could probably become sort of an "Einstein" in your college/school as well later on when you start working.
10. http://www.quora.com/ – The place where you find out about answers like this one :).