Last night at dinner, a friend asked me "So, how did you learn photography?"
I told him a long answer about the one photography class I had in college, about how I used an SLR to photograph my paintings. I told him how I started using digital cameras around '96 and got my first digital camera, a 0.5 MP Kodak DC50, in '97 and started feeling that digital was a lot more like painting than film was--it clicked with my brain. I started my first web site. In 2000, I bought a Nikon CP800. By 2003, I bought a Nikon CP5700. I was an internet forum junkie. In 2004, I started entering contests and won over 93 "Picture of the Day" or "Picture of the Month" awards in 18 months. I bought my first digital SLR camera. I showed my photography alongside my paintings in exhibitions. I sold my photography through galleries. I started selling them as stock images. I started shooting photos for a few local and regional newspapers and magazines. In 2005, I joined the National Press Photographer's Association. In 2007, I started shooting models, which led me to photographing paying clients. I joined the American Society of Media Photographers. I've shot corporate work, Archbishops, Presidential candidates. I've had my photos licensed in over 20 different countries. I'm happy to say that I've left my teaching position now to focus on my photography exclusively, and to develop it further.
That was a long answer, and I know it wasn't what he really wanted. The real answer goes something like this: You learn through asking the right questions--and making friends with people who are willing to answer those questions.