Doc's question about having to run a 10k before the half, along with a conversation I had with another Dad via text last night, got me thinking. And that's never a good thing....
While I told Doc that you don't
need to run any type of race before the half marathon, you really, really
should. For one, 13.1 miles is a very lofty goal. Clearly it's an attainable goal (Look at Tim and I), but if you get off one of your early training runs having ran just a few minutes at a fairly slow pace and feeling like your legs or chest are about to explode it's quite easy to get into the mindset of "I'm never going to be able to run 13.1 miles!"
So go find a 5k in your area. Most registrations run about $25 and you get a sweet t-shirt and sometimes a goodie bag.
http://www.runningintheusa.com/Race/Default.aspx is a good resource to find races, as are local running stores or local running clubs. A typical couch to 5k program is about 9 weeks long. So find a race that is around April or May. That will give you enough time to finish the training and give you a goal that is much closer and easier to attack. It will also give you an idea of what it feels like to go through packet pickup, get lined up for a race and compete with other runners. (Hint: it's a rush. Even if you come in last place, just being out there is an accomplishment)
Once you get that first 5k done, start working on longer distances. Another 5k, or 8k or 10k. I did 5 races from the time I started training last year to half in January. (5k,10k,5k,8k,15k). Each one gave me a tangible and reachable goal, all the while keeping me on track for the ultimate half marathon race. They're also a lot of fun - the Packers put on one where you got to run through Lambeau Field. Another raised money for the local Children's hospital. One race was just days before Halloween, so a ton of runners were in costume.
So don't get discouraged if you're not running as fast or as long as you want to be. Training takes time, but you've got a lot of time to go before January 11th.