Another really terrific way to get up to speed on Photoshop--is to find a good teacher in your area--and sign up for some private lessons. I teach, in my area--mostly photographers, who want to learn Photoshop--and I've recently had a student sign up for a series of five lessons, who has indicated that he learned more from me, in one lesson, than he learned from a semester course, at a local college.
As a former professional actor--with MANY years of private lessons on all sorts of subjects--I would have to agree that you tend to learn MUCH more--and much more quickly, in a one on one scenario. (Of course--it helps to have a good teacher--and to RELIGIOUSLY do your "homework" between lessons! ;-))
I've had long-term students, but the majority of people I work with come to me for just a few lessons--I generally recommend at least two, one and a half hour sessions, with at least two weeks between sessions--so the student has ample time to practice, before their next lesson. That can be enough to get someone up and running--although 5 of those lessons, spread out, can give a good, solid foundation, and cover more subjects...
Having someone to take your questions to--and to guide your mouse, initially, when you're trying to master layers, layer masks, and blend modes can save you hours of frustration--and leave you in a good position to go off and do your own explorations after that. :-) (Plus, with private lessons--everything is tailored towards YOU--what YOU want to learn--and how quickly--or slowly--you do it! :-))
And personally--I recommend Katrin Eismann's book, "Restoration and Retouching" to ALL my students--as the one book they should buy, if they're serious about learning to use Photoshop. I don't think there's a better book out there that explains the nuts and bolts of how to edit your images in clear, easy to understand (and follow!) English. It's the book I wish I'd had, when I was figuring things out on my own! (I've got a shelf full of terrific
PS books--but so many of them leave out one crucial step or piece of information--so you're not able to follow along completely, if you don't already know your way around Photoshop--so they can be quite confusing to a beginner.) As superfrasky mentioned--Eismann's got a new edition coming out this month, supposedly--so you can either wait a few weeks, and pick it up--or else pick up a used copy of one of the older editions for a bargain price, on Amazon.com. :-)
Best of luck to you, however you decide to learn--and don't forget to HAVE FUN with it!!!! :-)