As a fairly new photographer who is interested in learning more about the advanced settings on my Canon 7D, and less about Green / CA modes, can you share the areas of photography which forced you to put the camera down, and head to the book or the web? Are there elements of photography which simply can't be learned through experience? What pushed you to read more about it, rather than shoot until you got it right?
I'd flip your question, as in what aspects that you picked up from a book or website really enabled my photography.
Fundamentally, I think you need to read the manual that came with your camera. Its boring, but do it anyway. Read it all, like a novel with your camera in your hands. Then periodically read parts of it, in depth, again.
I had a lot of experience shooting with available/natural light, and I really disliked the results when I used a flash/strobe. This changed when I started reading books and websites from folks like David Hobby, Joe McNally, and Zack Arias. I found that for a modest amount of money, far less than a lust-after lens, I can get lighting gear that greatly improves my photos of people.
Not sure this question can have a definite answer. I'd say it depends on your personality.
Mine makes me avoid experimentation! I prefer learning and knowing what to do rather than trying. So when I see something that I do not know how to do, I read up as much information as possible. This is how I started photography.
However, there comes a point when I was reading more books and essentially getting zero new information, so I moved on to other forms of learning: Seminars, classes and workshop. At one point, I had to see how people were doing things which is where the workshops gave me the most improvement.
It is important to focus on those books, classes and workshops from the people who have a style and subject matter similar to what you are striving for. For me this meant I hated Joe McNally's The Moment It Clicked (which Amazon took back easily) and loved National Geographic's Photography Field Guide series. A must read for anyone wanted to improve composition is The Photographer's Eye.
Ten years later, I teach photography in group and private classes. My students usually are looking for answers. Most have done very little experimentation because they would not have known where to begin.
With unlimited amount of time and resources, experimenting will get you everything you can find in books and more… one day. I think for most people, not reinventing the wheel is the faster and easier path.
Experimenting is the best way to learn - if you know what to experiment with.
Experiments let you understand how specific small details work but they don't let you discover new techniques and effects you don't already know about.
For example: aperture size changes the look of (in focus) light sources, large aperture makes them glow and small aperture creates starbursts - the best way to really learn how this works is to point the camera at a light and take pictures at different aperture sizes - but if you don't hear/read about this how do you know you should experiment with pictures of a light source at different apertures?
Same goes for soft vs. hard light, to really understand the difference you need to take pictures in soft and hard light and look at them - but if you don't know what soft/hard light is or how to create a soft/hard light source you can't do this experiment.