A little collection of websites:

It is targeted for everyone interested in the field.

The Basics:

• Lecture notes Structures I from MIT
• Civildigital: great Articles on nearly everything civil engineering related
• Want to test your knowledge? Quizzes on the basics of civil engineering subjects.

Skyscrapers

• Skyscraperpage.com a great database on Skyscrapers 

Construction

• The Constructor: Mostly focused on hands on construction itself