Running is a pain in the foot

My left foot is acting up. I'm experiencing a dull ache on the bottom of my foot after runs and first thing in the morning. After some web searching, I believe I found the culprit (plantar fasciitis). Maybe I'm jumping back into running too fast, maybe I'm not properly stretching, or maybe it's time for new shoes. At least I'll fix at least 2 of the 3 problem areas. My new asics Kayano XII are in the mail and I stumbled across an Achilles Tendon Stretch and Plantar Fascia Stretch via runnerworld.