The providers of the Conductor plugin have compiled an extensive guide to developing with WordPress. There are links to free and paid tutorials, as well as podcasts and books, and they are accepting submissions to the guide through comments to the post. The guide highlights best practices and is pretty thorough so far. If you have development resources, free or paid, why not go over there and add them? I have not checked to make sure all of the listings are accessible, specifically the paid ones, and I do not think the books are available on Bookshare. Most of them are, however, available on Kindle, which you can use accessibly if you have an iPhone, iPad, or iPod current model. The guide is an excellent resource whether you’re just getting started with development or have any level of experience in that area. It’s definitely worth adding to your bookmarks/favorites if you’re interested in development for WordPress in any way, whether that be for themes, plugins, or core code.