So, I was just reading recent questions and ran across: https://drupal.stackexchange.com/questions/24381/any-good-books-tutorials-on-drupal-for-an-advanced-php-developer
This is a near duplicate for a few other questions ( https://drupal.stackexchange.com/questions/16922/where-can-i-find-tutorials-about-drupal-or-e-books, https://drupal.stackexchange.com/questions/6050/what-is-a-good-book-for-learning-how-to-develop-drupal-7-modules , and likely others), though this one is framed a little differently.
If this wasn't a new DA user, I would vote to close this as not being constructive as all answer could be considered correct. Also, several of the booklist questions are those involved in the current brouhaha on the main Meta site.
Personally, I don't think these are really good questions, primarily because the answers aren't timeless. Though programming languages do change over time, the good references still stand.
Drupal however does change, and API changes do mean that some books and tutorials are flat out wrong. Most of the examples in K&R 2 that show use of stdlib functions are still correct and will work, but many of the examples in the first and second editions of Pro Drupal Development will result in problems because the API has changed.
So, what should be done with these?