I did the Cool Running Couch to 5K plan (or rather jumped in at about the middle after doing some work on the treadmill at the gym.) It worked pretty well for me! As the plan says, listen to your body and don’t be afraid to repeat a week. Everyone improves at their own pace, and there are a million factors going on in your life (illnesses, stress, nutrition) that impact your ability to train. And remember, even if you’re repeating a week, you’re still improving at a much greater pace than if your butt was home on the couch!
Another reason to listen to your bod is that if you noticed that your feet / shins / knees have begun to bugging you, don’t assume that you should just put up with it. Get yourself some new shoes, 'cause your old ones are busted! Don’t cause yourself unnecessary pain (or injury!) Another thing you can do to reduce the chance of injury is to talk to your trainer about resistance exercises to strengthen your ankles and knees.
And I second the advice to get a heart rate monitor if that’s possible. A really simple one is really all you need (though do get one with a stopwatch, you don’t have to wear a second watch.) Treat it as a measuring tool, and do not to let it dictate your workout. Check out your heart rate as you warm up, when you’re feeling good, when you’re feeling crappy and out of energy, when you’re feeling like your lungs are on fire, and as you’re cooling off. You might discover some useful patterns. Frex, I noticed that in the middle of the “aerobic” range (based on my age), I felt miserable, like I was slogging along, but if I could up my HR to the upper end or even a little over, then I started to feel great, like I could go forever. I also discovered that if I got much above a certain limit, my HR would shoot up and I would tucker out and get sick to my stomach. So take the recommended limits as a first guess, and find your own body’s favorite zone—and expect it to change as you keep training!
Anyway, nurture your hate. Feed on it. Why are you going to start running? Because you fucking hate it. Because everybody fucking hates it. But when you do it, you will be proving that you are a fucking badass. When you mention offhand that you’ve taken up running, you know what people will think? They will think, “My god, Zsofia is such a badass!” When you start reaching those milestones, running 5 minutes continually, then 10 minutes continually, then 25 minutes, you know how you will feel? I’ll tell you how you’ll feel . . . you’ll feel like you’re going to fall over and die, that’s how you feel. But then you’ll drag yourself home, and you’ll get in the shower, and you’ll finally start to feel human again, and you’ll say to yourself, “By God, I did it! I am a complete and utter badass!”