I completed the learn to run program for the VAncouver Sun Run, and if I could do it, ANYONE could. There is a fabulous page which includes a training program (although if you have time, I would spend two weeks at each level before moving on to the next). And GOOD shoes are essential...go get fitted properly at a running store:
http://www.sportmedbc.com/sportmed....training_run10k
Just as an aside, I did this program when I was fresh from my third pregnancy, and very overweight. I was completely out of shape, so much so that I could not complete the WARMUP at first. I really struggled, but if you do your three sessions a week, your body will rise to the challenge.
Note that I did not run the entire 10k, I did a 75% run, 25% walk. Most people use some form of run/walk to get a better time and reduce the risk of injury. A goal for "later" can be working up to a higher ratio of running to walking over the course.
Other points: most people I know have some trouble with minor injuries and aches and pains when they learn to run. Do not let them discourage you, but do let your physiotherapist help you with quick treatment and good advice. I developed a knee problem that went away completely after I followed my physio's advice to switch to powerwalking till the knee healed and was stronger (I also did stretching and strengthening exercises for my entire body). Later that year I developed a fairly severe achilles tendon injury that also completely vanished after I followed my physio's advice on treatment and rehab. Runners know who the best physio's are, so if you need a reference, ask around.
Best advice: do a 10K walking program first if you are really out of shape. That will give your frame time to build muscle that keeps you protected from injury.
Ramp up slowly, but work out 3 x per week.
If it hurts, back off and do last week's program again.
Leave out the hills till late in your training.
If you are treadmilling, use a minimum grade of 1 to simulate running on the ground (which is not helping you out by moving under your feet).
**Do core and ab work to help stabilize your shock absorbing system.**
Have fun, running is very empowering and great for the weight loss!