+1 to the advice above. I've also run a few halves and several full marathons and agree with the general advice above:
Don't overtrain (a common mistake). Almost all running plans have some different iteration of a "staggered" plan, where you slowly increase your mileage, reaching your highest mileage a few weeks before your race.
Start with getting a good running "base", where you can run a "long" run once a week (around 5, 6 or 7 miles) and run 2-3 short runs during the week (like 3-4 miles). Keep this base for 2-3 months (at least). Keep it fresh by trying out some group runs and finding different places to run in your area.
Once you have this base, start increasing your "long" runs by no more than 1-2 miles, then back off the next weekend to your base miles, then increase the next weekend and so on, staggering until you reach your goal mileage. For a half, there is no need to actually run 13 miles before the race, but you can, as it won't really break your body down like trying to run 26 before a marathon. What I mean is that if you can run a few 11 mile or 12 miles runs about 2-3 weeks before your race, then you WILL finish your half with no problem!
Do you currently run with a partner? A good way to get excited about a race is find someone to run with and to pick a race that maybe benefits some organization you like.