The most exciting thing about this race is that I
Find a Training Plan
A good training plan is key to having a successful race. When looking at plans look at the volume of running in the plan, the suggested cross training and the time you have available. I am a huge fan of the Jeff Galloway training plans and have used these (or a variation on them) for all my races.
Figure Out Your Nutrition
This is one of the hardest parts of training and is different for everyone. I have tried just about every product on the market and know what works for me. Unfortunately, that doesn't necessarily translate to others. Honey Stinger Chews are one of my favorites, but they are often more expensive than other options.
After much trial and error I will normally do toast and peanut butter before and race and then something about every 45 minutes.
Get Fitted for Shoes
Do this early. The right shoes make a world of difference in both training and racing. This is another area where what works for me, won't necessarily work for you, but find a good local running store and they can help you out. Manufacturers also change their shoes over time, so the model you are running in and the current model may be very different.
Body Glide is your Friend
Unless you don't sweat or no part of your clothing or body rubs another part (and in that case can I be you?), you will want to pick up some Body Glide. Chaffing is no fun, but it happens to just about everyone. A good coating of Body Glide will make that first post run shower a little less painful.
Cotton is Evil
I know...races are expensive and you don't really want to spend money on expensive running gear. You can find relatively inexpensive running or workout gear at a number of places (Kohls and Old Navy are some of my favorites). Your skin and body will appreciate being able to breath.
This is a big one. I have run halfs with training that was spotty at best and halfs where my training has been consistent. The ones with consistent training were far more enjoyable. While life happens, this is why picking a training plan that works with your schedule is so important.
The more I think about these, they really apply to pretty much any distance. What advice would you share with those running a half marathon for the first time?