My best advice to frndshpcptn is to start early in the year and build up very slowly. I entered my wife in the 1/2 as a birthday present in February (I know, Cary Grant I'm not), and at that time she had good base fitness from working out regularly, but could probably only run 2 miles max if a bear was chasing her.
She started with 1's, 2's, and 3's, and as spring turned to summer she very gradually increased her miles, and by August she was able to do 8. She ran a 10k in October, and her comment was "I never thought I'd call that a short distance, but it was." She was up to 10 by Halloween, and she stretched it out and did 12.5 miles on December 11. Right now she's tapering and raring to go, and is absolutely certain she will finish the 1/2 without much pain or difficulty. In retrospect, she pushed her long run out at a rate of 1 mile each month.
Finally, if you're feeling an injury come on (sore does not equal an injury, you'll know the difference), back off for a bit. Far better to do less and let it heal than continue to push it, ignore your body, and end up on the disabled list.
Good luck on, I assume, January 8, 2006.
And sorry, I'm not bringing anything from Massachusetts, not even the 40 degree weather today. Cooler would be nice, but I'm outta here.