If you're having problems positioning your fingers properly, you need more than just a picture from one of your favorite books, find a way to jam with someone else and study his'her fingering like theres no tomorrow. Yeah from the very beginning, I found it rather difficult to form certain chords properly, but its all about finding your sweet spot, :). Learn to relax your fingers instead of putting excessive pressure on the fretboard and everything should fall into place. The best way to get the most put of your practice time is to work on two or more things at once, and don't be afraid to improvise.

-Joseph