I am diving into magento programming and am looking for a structured introduction. Unfortunately I do not find much, but some books on magento 1.3 (I'm not looking for administration, theming or how to increase sales, I'm looking for sys architecture, extension dev and so on).
Since I'm coming from typo3, I know that two years can include game changers (extbase in typo3).
So, are books for 1.3 still recommendable? Are there any other structural resources that go beyond HELLO WORLD?
EDIT: I'm as well looking for hints regarding the main gaps between 1.3 and 1.7 and how to fill them.