My disclaimer is that I had never run competitively until about 1 1/2 years ago. I am completely self-taught by reading and watching articles on the internet, what friends have told me, etc.
I have trained myself to run 5Ks. A very commendable accomplishment. Now I would like to expand my running to a potential 10K. I keep hitting brick walls. I finally went and get got fitted for a pair of 'real' running shoes (Mizuno) from a real running store. This helps significantly, and a vast majority of the pain is gone. My other wall seems to be energy/stamina/time. I run a lot, but do not seem to be improving on actual speed. My one-mile time has improved to a little over 7 minutes.
What is the best way to safely enhance the training that I do now and expand upon my distance? I currently run about 2-3 miles on most days with some days just simply doing about 1 or 1 1/2 miles. I have also been doing some additional training with cycling (2-5 miles per day). I do not do any additional cross-training at this time.