PeepCode - Even their PDF books are awesome
This is obviously not my first time that I have shilled the PeepCode website. I truly think that for any Rails developer, this is one of the most invaluable tools for learning available anywhere. I've purchased many of their screencasts already, and once I get the opportunity, I'll even spring for their PeepCode Unlimited subscription. I know I will fully get my money's worth.
If you haven't been following what they have been doing recently, they have also added PDF books to the mix. These books provide a lot of wealth, just like their screencasts, but only in text form, perfect for printing or, for the environmentally-conscious of you, just keeping in your flash drive and reading it whenever you need it. I just recently purchased two of their PDF books: Git Internals and ActiveMerchant.
I purchased the Git Internals book to satisfy my own curiosity. As many of you should know by now, Git is a distributed version control system (a la Subversion) that's taking the software development world by storm. I'm slowly getting into Git, thanks to a PeepCode screencast on the basics of Git, and even decided to pay for an account on GitHub (which I will write about in the near future). But I'm usually not content to just know how to get my work done. I like exploring beyond that, knowing how it actually works in the inside. Most of the times, I fully understand its strengths (and weaknesses - nothing is perfect!), making me more efficient. This PDF book does exactly that. If you're a curious being, and are using (or planning to use) Git, I wholly recommend this book.
The ActiveMerchant book, I actually bought out of necessity. The web application I'm working on has the ActiveMerchant Plugin installed, and some work with that plugin done. However, since the developers who implemented those features aren't working for the company anymore, and some core functionality has changed since I've arrived, it needs to be changed. I didn't want to start from scratch, so I bought this PDF book to see what should be the "right way" (as per the author, who undoubtedly has tons more experience with the plugin as I have). I really got into this book, because it's really, really easy to understand (thanks to the plugin actually being easy to implement) and it explains everything you need to know about the entire payment process. This is a must-read for anyone who's building Rails applications where money needs to get to you.
The guys over at PeepCode are doing an excellent job, so why don't you head over to their site and check them out? If you're a web developer, particularly using Ruby and Rails, you'll definitely find something interesting, or even necessary.