What do you think constitutes "junk miles"?  Let me put it this way.  If you design your training plan so that each run has a purpose - base-building, speed, recovery, long, etc. - then none of them are junk miles.  I think the main thing is to listen to your body, don't overdo it or push too hard, take days off when you're tired, and watch your form.  If your form starts to suffer, it's time to back off for a few days.

You should be able to use one of the online plans, maybe adapting it to your desired weekly mileage and workouts (speed sessions, etc.).  Possible sources include www.halhigdon.com, www.runnersworld.com (SmartCoach), and Active.Com - http://www.coolrunning.com/engine/2/2_4/144.shtml.

As for the 8 minute pace, that depends on you and where you're at, training-wise.  Has your training the last couple years kept you capable of that kind of pace?  If you're not close now, you're not likely to get there by Oct. 31st.

Len

I agree about the Runners World programs.  I ran a half marathon 18 months ago following the "Your Ultimate Half Marathon Program", and I modified it by blending the intermediate with the advanced program. Last year I trained for a 15k by following virtually the same program though it was a little more the advanced than the intermediate.  I got great results both times.

Also, I use the McMillan calculator to determine my training paces.   http://www.mcmillanrunning.com/mcmillanrunningcalculator.htm  The paces suggested by the Runner's World program are based upon the pace you would like to run the race, and that is not usually a good way to determine your workout paces. Rather, base that upon your current fitness level, and let the calculator provide you with the tempo paces, interval paces, long run paces, etc.

Good luck with your half marathon!

Brian