Read everything on Jakob Nielsen's blog about Usability: http://useit.com/
Everything from there has been sort of copies. I find it more interesting to dig into the human brain and related books. Ie. cognitive psychology and how our brain perceives things. The difference between cultures etc. That's where you really learn the WHY and HOW.
http://www.amazon.com/Think-Common-Sense-Approach-Usability/...
It's more of a usability book, but it covers some visual aspects to design. Beyond that it comes down to reading, practicing, critiquing and being critiqued. Any time you visit a new website think to yourself: what looks good, what looks bad, what is intuitive, and what doesn't make sense.
Here are the resources I drilled out of the threads I came across:
Type: http://www.amazon.com/Logo-Lettering-Bible-Leslie-Cabarga/dp... http://www.amazon.com/Graphic-Design-Manual-Principles-Pract... http://www.amazon.com/Elements-Typographic-Style-Robert-Brin... http://www.amazon.com/Non-Designers-Design-Book-Typographic-...
Usability: http://www.amazon.com/Think-Common-Sense-Approach-Usability/...
Design: http://www.amazon.com/gp/product/1592532616?ie=UTF8&tag=... http://www.amazon.com/gp/product/1592533485?ie=UTF8&tag=... http://www.amazon.com/gp/product/159253192X?ie=UTF8&tag=... http://www.amazon.com/gp/product/1592532349?ie=UTF8&tag=...
Web Design: http://www.amazon.com/gp/product/0975841963?ie=UTF8&tag=... http://www.amazon.com/gp/product/032145345X?ie=UTF8&tag=... http://www.amazon.com/gp/product/1847192505?ie=UTF8&tag=... http://www.amazon.com/gp/product/0735712069?ie=UTF8&tag=...
Sites: http://dribbble.com/ http://www.deviantart.com http://forrst.com/ http://lookslikegooddesign.com/ http://webtypography.net/toc/ http://ui-patterns.com/
It's a quick read that will give you tons of "A ha!" moments.
A must read.
http://www.amazon.com/Dont-Make-Me-Think-Usability/dp/078972...