Visualizing can help with some sports, but I think with horses you must first kind of relax and let your mind go blank before you get on. The thing is to tune into what the horse is feeling at the time. I know that right now you are focused on learning to ride, and that's what you should be doing, but all riding must do the tune in thing.
A lot depends on your goals in riding. At some point, most riders decide to either keep with riding a lot of different horses, or go for a certain discipline with one. You'll figure that out as you go along.
Probably a lot of people just read journals. If you pose a question you will probably get some responses. I like reading these journals because it is a real portrait of what is going on, not some pie in the sky blather.