The cost of books has risen to an astonishing level. It's hard to feed your lust of the written word when a new book costs $25. Fortunately, there are some great ways to save some money while reading as many books as you'd like.
Amazon.com is my first go when I have a specific title in mind, but I don't order from Amazon. Instead, I check out the Amazon Marketplace where I can buy used and new books from individuals. Some books are still pricey, but others can be found very cheap. Some books (especially older bestsellers) can be found for a penny; with shipping it's $4 for a book. This is a great deal if you are looking for a specific title.
Paperbackswap (paperbackswap.com) allows you to give your books to other readers and then pick out books for yourself. When you sign up, you are given 2 credits. After that, to earn credits you list your books to trade. When someone requests a book, you ship it at your expense. Then when you order a book, you pay nothing for shipping. This is even cheaper than Amazon, as the shipping is usually around $2.50.
Thrift stores don't usually have an amazing selection, however the price is right. Chain thrift stores usually charge around $1-2 per book, but the smaller stores sometimes offer them as low as $.10. Even with the limited selection, I occasionally find a specific title that is on my wish list.
Yard sales have an even poorer selection, but prices are good. Sometimes I'll find a box full of similar books (romances, mystery, etc) and will make an offer. Once I got a box of 100 books for $5.
Library sales are great. The selection is usually pretty good, and it's sorted by genre or topic. Prices are usually $1, or less for children's books. At my library, the last day is bag sale day where I can fill a bag for $3. I carefully fit the books into my bag and can get between 30 and 50, more if they are smaller kids books.
The library itself is the obvious go to. Any book you want is there or can be requested from another library. There are books, children's books, audio books, magazines and more. You can enjoy it all for free. I always read a book from the library before adding it to my wish list.
Sharing with friends is great if you have a similar taste. You might want to write your name in the cover so it doesn't get confusing.
Project Gutenberg (http://www.gutenberg.org/) is a wonderful online resource that boasts free access to 36,000 books. You can read online, with your portable device or listen to audio books. A link to affiliates gives you access to over 100,000 books. You could be reading for free for a long time with that.
Amazon offers some free Kindle books. If you don't have a kindle, you can still download the free Kindle app. A search of "free ebooks" pulls up many, many websites. Also, if you are subscribed to any e-newsletters, check their websites for any free ebooks.