I'm going to go against the grain for a second, here... (and, this is just my opinion, so, don't shoot me.
)
One thing you might find if you end up buying books and magazines is that it may inhibit your artistic freedom and flexibility. The other is that it may become a bit of information overload and you'll get bogged down. The other negative is that you will see one way of how to do something, and end up using just that one way. Your images will end up looking like everyone else's.
I've never owned a book on Photoshop, and, have perhaps read a handful of tutorials (colour merging, split toning, and a couple of other esoterics).
The best way to learn is to simply dive into the deep end and learn to swim, because the best part about it all is that you cannot break anything. As a consequence, you'll define for yourself a unique style.
As mentioned before, the help menu in Photoshop is chock full of goodies that gives you all the grounding you need, in order to push yourself a little further each time you work on an image.
My 0.02 cents, GST included.
Regards,
Humayun