This is a list of locations I find interesting.

    1. General science links
    2. Physics
    3. Mathematics
      • Paul Bourke has a great deal of resources. Those regarding geometry I found really helpful
    4. Resources for programmers.
      1. General programming
      2. Assembly
        • MASM forum is where I've learned a great deal about assembly
        • Flat Assembler is a great tool, especially that it's open source and free
        • Bogdan Ontanu is writing an assembler and an OS. See screenshots and download.
    5. Resources for surveyors
        1. Pedro Maciá García  has done a great job with LandDTM, enabling the surveyor to do a lot of interesting stuff. 
    6. Others
    You may find it... interesting.