While there are no doubt some "natural image makers" who are just born with the knack, I think most of us have to work hard learning to create compelling images. There is a big difference between taking a picture vs creating a compelling image.
Beginners often want to know what kind of camera you have, what ISO are you shooting, that kind of thing. Those that have spent time practicing know that your brain is the most important piece of photographic gear! You have to train your mind in this art.
Over the years, I would say my best source of information is the web. Photographer's sites, and sites where people share and critique photos such as www.photo.net and www.fredmiranda.com have been very helpful to me. On sites like these, you'll always find people with more skills than you, and you can get inspired and learn from their images.
After the web (and of course besides getting out shooting!), I find photography books to be quite helpful. I probably have 50 or so photographic books.
I recently came across Creative Nature and Outdoor Photography by fellow Northern California photographer Brenda Tharp (www.brendatharp.com). Here is a link to the book on Amazon. For me, a great photography book has images on nearly every page - excellent ones. Many books are trying to help out people of all levels ("get a sturdy tripod!"), I prefer those that focus on images, learning how to see and challenging me. If the pages move me to say "I want to go make an image like that!" then I know it's a good book for me.
Brenda's book takes you through the properties of light. Might sound simple, but mastery of light is what all photography is about. It has quality, color, direction, intensity. Beyond light, composition is another vital element of great images. The book covers perspective, scale, dominance of elements, proportion, rhythm and more.
What separates her book from many others is that each concept or technique is shown with several excellent images representing the concept. Between the words and the images, its clear what she means by "Expressing the Mood" and other subtle concepts.
Here are a few images from Brenda's book and website:
Lines and Color
Expressing the Mood
Capturing Gesture
Most aspects of nature photography (and a fair amount on people as well) are covered, including several I haven't thought of or seen before. There's a great section on evaluating your progress as well.
The challenge, my friends, is learning to see, being creative and continually working on each of the skills required to discover, compose and render compelling images. As this book is helping me, I highly recommend it to help you get there too.