I work in the child care industry. and we did a newsletter with Comic Sans body text for several years, it was a very friendly font to use, also quite readable. Our clients liked it.
Given what I see in publications, design books and sites that some professionals call 'good' or 'cutting edge' design I have see far worse issues in approachability/usability/readability than using Comic Sans.
The ones I've found that are good starting points:
Stylin' with CSS by Charles Wyke-Smith - its mainly a (good) CSS book but gives enough hints at good design so you don't go overboard.
Handcrafted CSS by Dan Cederholm with Ethan Marcotte - again CSS tutorial with emphasis on good design with CSS.
Once you get the handle on those (or before hand) check out the great examples in CSS Zen Garden. ( http://www.csszengarden.com/ ) Something you can pick apart and analyze. The cool thing about ZenGarden is the HTML is always the exact same file it's the CSS and graphics that make the designs different.
Beware web design books that concentrate purely on web design - some of them are trying to be too artsy and cutting edge, look inside the book before buying... also some may be specific for templates in WordPress, Joomla or some other CMS.
I find dokuwiki to be a great wiki - does not need a database if you don't want one. Stores data as text files and images, so easy to look at source data. The access system is nice, can set up access groups. With the right template you can make it into a nice little CMS. Have used it at work and Staff seem to be able to get a handle of it pretty easily.
Yeah I looked, and they even have versions for Windows Mac and Linux. Once they add in mobile support they have it pretty well covered for all platforms. I don't think facebook/skype has the same support level.
In some situations you may be data rich but function poor. Like embedded devices where you have a limited instruction set, 128bytes of RAM, but access to megs of ROM for program/data.
Programming PHP - O'Rielly its not the cutting edge book (2006), but it is by PHP founders and a good ground-start to get a feel for the language and what the commands can do. I learned quite a bit more on how many of the commands work than what other books covered. You will still need a good OOP book,
for OOP I've liked PHP Objects, Patterns and Practice by Matt Zandstra
Some Classic Computing Non-Fiction (circa 80s and earlier):
* Soul of a New Machine - Tracy Kidder
* Fire in the Valley - Paul Freiberger and Michael Swaine
* Hackers - Steve Levy
* Commodore: A Company on the Edge - Brian Bagnall (get the second edition)
* The Psychology of Computer Programming by Gerald M. Weinberg - for being written in 1971 (with an updated edition in 98) it is very interesting and still relevant.
* Coders at Work: Reflections on the Craft of Programming by Peter Seibel - interviews of many luminary programmers, how they got stated and what they have done.
In case its a case of not 'getting' bitmap editing... You might consider a vector editor - like Illustrator or Inkscape. Works more like a programmer's mind; where you need to tweak elements and can always go back. Photoshop doesn't always give you that flexibility.
There are also tutorials on-line on doing buttons and such for inkscape/illustrator.
Think of errors I had probably missed before I started compilation. Just about any long process I think of the stuff I forgot to check before I initiated it. :-D
Other than that I get up, take a break, I deserve it.
Given what I see in publications, design books and sites that some professionals call 'good' or 'cutting edge' design I have see far worse issues in approachability/usability/readability than using Comic Sans.