I did a 5k last weekend and realized that I needed to keep working on my long distance runs. I had fun doing it, but didn't like the time I ended up with. GH, how did yours go?
AUT1, fleet feet in Huntsville does the couch to 5k program, and they provide you with a running coach like GH was talking about. Fleet feet also has insoles that can help with your knee and ankle pain. You are welcome to come run the snake infested cross country trail with me anytime.
I usually go in the 18:30-19:15 range during Spring/Summer races. Just depends on the course and if its hot/humid. I ran 18:51 Saturday and got first in my age group. I am really aiming to trim about 10 more lbs and shoot for 17:59 by end of August in a big night race in Columbus (3,000 runners).
Fleet Feet is a good store. They are a chain so they are also in most major cities as well. Ive been to 3 of them now: San Antonio, Birmingham (on 280 near Summit) and Savannah. Excellent stores and they offer great support.
AUT1, try the insoles that ssg speaks of. Also try taking some Condritin + Glucosamine + MSM/Osteo Bi Flex. Combine that with some weight loss and some insoles, that will at least make exercise manageable for you. The supplement I mentioned above will actually help rebuild and repair your joints. I take it religiously. When you get your base back, it's also worth it to get a gait analysis at somewhere like Fleet Feet. They can hook you up with some shoes that will help your mechanics and get you in a more natural running form (zero drop shoe, mid foot strike).
Here is what I run in and I stay pretty injury free in them. They are designed to get you more in a natural running form without injury. Fleet Feet should have them:
http://www.newtonrunning.com/shoes