I teach Art Journaling at my LSS, mostly as a way to teach techniques. I recommend visiting Julie Fei-Fan Balzer's website at this link: Balzer Designs: Art Journal Every Day
Perfect for beginners, to answer all your questions, as well as offering challenges for those that are advanced...to help stretch your creative edge. Julie has some fantastic YouTube videos as well, for those that prefer a more visual explanation.
Hope that helps.