I personally never learn a lot from these books. The only one I did learn anything from was some book, I borrowed from a friend, that covered music theroy. Once I understood that, I could build any chord I wanted and at least had an idea how it should be used. I also understood scale structure better, which improve my improvisation skills.
Since I have recently started playing again, seriously anyway, I have simply followed my normal practice regimine from back in the day. Doing this allowed me to get back to basically the same level of playing ability that I was at when I stop all those years ago, within a matter of weeks. At this point, since I don't have a bunch of CD's laying around and I'm currently on dial-up again, I am searching the net for tabs of songs that I have heard and want to learn. And believe it or not, it has really helped me alot.
This is how I actually started playing. I bought different guitar magizines for months before I got my first guitar. I took that time to learn how to read TAB, so that when I did get a guitar I could start learning stuff right away. After a month or two, I keep hitting a wall so I took some lessons from a local guy named
Steve Azar and he got me going in the right direction and helped me set-up a practice routine. I sorta took it from there. When I found something I couldn't play, I would analyze the hell out it and come up with exercises. These exercises would help me develop the proper technique or strength to overcome whatever weakness I had, in my playing, that keep me from playing that part.
Like I said before, I started doing this when I decided to start playing again a few weeks ago. In that small amount of time, I was able to jump leaps and bounds. Just this week alone, I have improved my right hand speed enough to allow me to play Anthrax's "Caught in a Mosh". For some, that might not seem like much, but for me... I was over joyed. I have also been able to improve my left hand accuracy enough to allow me to play most of Megadeth's "Holy War", which I still feel is one of the greatest metal songs of all time. No, I take that back. It's not a song, Holy War is more of a composition. Anyway... I digress. At the sametime, I was also able to learn the beginning lick of "Green Tinted Sixties Mind", by Paul Gilbert of Mr. Big. I still don't have it down perfectly and might not be able to hit every note everytime, but at this point I am happy. The rest of the accuracy will come with more practice and time.
Most of all... Don't expect to grab onto something the first time you try to learn it. Remeber to analyze your mistakes and come up with exercises that will help you reach your goals. And most importantly, start including those exercises into your warm-up routine. And if you don't have a warm-up routine, start one.
God! I hope I didn't bore the hell out of you with all this.