Here's a topic that's near and dear to me as a writer: books. Another thing I consider wonderful as a technophiliac is open source stuff. Now, combine those two and you get Open Source Books! It's a wonderful concept that combines the free mentality of source code with literary and informational texts. It allows the average person with internet access to have a library of extremely useful information at their fingertips, and it's a whole lot cheaper than taking classes!
One of the first places I ran across when Googling up open source books was the O'Reilly website. For O'reilly's open source books, they use the Creative Commons License which is somewhere between, as they put it, all rights reserved and no rights reserved. My general understanding of Creative Commons is that the license a little different with each book, and you generally can't edit and redistribute the book with your name added to it like you can with source code in the GPL. However, you can find quite a few titles on here from books that are out of print or otherwise (for one reason or another) released for free as either PDF or HTML texts. These are useful for finding that tidbit of information you read somewhere but can't find anymore.
Another great resource is Archive.org's Open Source Books where you will find, to date, nearly 14,000 books in various languages. They also have a section for the old Project Gutenburg that contains many older books that have gone out of print and are now in electronic format. PG has been on the net for a long time, and they've been providing free books to the world before it became hip.
Take advantage of these resources to educate yourself about a variety of topics.