If you're wanting to learn how to design, find as many design books as you can in the library. Not the Photoshop manual, but books like "108 essays on design". Find as many design mags as you can and read every article: Communication Arts, Print magazine, whatever. (Communication Arts puts out a few annuals every year: advertising annual (my favorite), photography annual, interactive annual, etc.)
Consume as much design as you can and write down what you like about what you like. Consume, consume, consume.
Then, just DO IT. Do, do, do. But without a computer.
Take out a piece of paper and design a landing page for your current project. Layout where your titles will go, where your form will go, etc. Photoshop won't help if you don't know what you want in the first place. Explain to someone why the form is on the left instead of the right. Explain why the title is so big and why you chose that much content.
Then rip it apart and make another. And another. And another. And just keep doing it and talking about it with people smarter than you and people dumber than you. Find online communities like Behance or Forrst or Dribbble and review/preview others' work.
Consume, consume, consume. Do, do, do. Talk, talk, talk. It's the exact same way you learned to program!
Books Web design Steve Krugman - Don't Make Me Think (and the sequel)
Presenting information
Edward Tuftes - http://www.edwardtufte.com/tufte/books_vdqi
Highly useful books about presenting statistics and information visually
I find that the articles on these websites focus more on the basics.
A List Apart - http://www.alistapart.com/
Design Shack - http://designshack.co.uk/
Photography It would be good to pick up some photography (even with a point and shoot), if only for the simple reason to provide some photos in your blog/marketing materials.
Inspiration Carbonmade.com Deviantart Flickr http://dribbble.com/ http://forrst.com/ http://lookslikegooddesign.com/
Other related topics You might also read up on User Interface Design (UX, UI..).
This quote might be useful A designer knows he has achieved perfection not when there is nothing left to add, but when there is nothing left to take away. ~Antoine de Saint-Exupery
Initial exercises: Try to re-create a page from a book or a magazine in Quark; try to re-create a logo or illustration in Illustrator; and try editing some photos in Photoshop.
There is no shortcut: all of this is hard work and will take years to learn.
If you want ONE book that has the absolute highest ratio of useful information to page length, the book you need is "Logo, Font, and Lettering Bible" by Leslie Cabarga. If you get that book, you will also want a copy of Fontographer.
Visit CSS galleries. Emulate specific elements. Combine them. Create your first site (when I started I pretended I was hired to do the marketing page for Dropbox). Then another. One day you'll be good.
Just keep at it. Good luck! Also, email me if you want more info and my old designs (they suck so it shows how far I've come).
They have great tutorials as well as a plethora of other things useful in learning graphic design.