The half is one of the most straight forward events to train for because performance in it is very much based on one thing your aerobic threshold. So training for it should be pretty straight forward. A lot of aerobic quality. You need not go any faster then goal pace, though I always recommend short steep all out hills to increase muscular strength and heart stroke volume, and you will see big results just by running miles.
How to prepare for the race depends on how fit you are, how many miles a week you can handle, how many hard efforts a week you can handle ect.
A nice series of half marathon focused workouts that would be easy enough to do though, one workout a week.
10-12x1k at half goal pace w/ 2:30 rest
5-6 x 2k at half goal pace w/ 2:30 rest
10x1k at half goal pace w/ 1k 40 seconds slower then goal half pace rest
4x3k or 2 mile at half goal pace w/ 3 mins rest
3x4k at half goal pace w/ 3 mins rest
10k tempo first 5k at 20 seconds per k slower then half goal pace 2nd 5k at half goal pace
3x5k at half goal pace with 3 mins rest
7x2k at half goal pace w/ 1k 40 seconds slower rest
10k at half goal pace (2 and half weeks before goal race)
4x3k at half goal pace 3 mins rest
5k at half goal pace
You can do another workout each week if you can handle it, a tempo one week and a anaerobic 5k/10k type the next would be my recommendation, if you can handle two workouts a week. Also i would recommend a long run every week and if you can do it without killing yourself try to finish it at least every other week with 1 to 3 miles on the track at your half marathon goal pace.