I think it's one of the hardest parts of running and I've even met long time runners who HATE hill running, some who will even go further just so they don't have to go up them. Hill running is a challenge and regardless of how long you've been running, hills always make you take notice. Personally I think including hills in running workouts is a lot like eating your veggies as a kid, they're good for you and it's a great way to get better. Preparation, if you are training for a 5K or something longer like a 10K, you never know when they are going to come along. A lot of races have a hill right at or near the beginning. The Turkey Trot I have done for many years, Feaster Five, is mostly uphill for the first mile of both the 5K and 5 mile. Going up hills is a great way to learn how your body will respond when you first begin a hill and it is important to realize that you won't be able to keep the same pace you had on the flat ground. Many people do hill repeats or run stadiums to get the benefit and the practice. Practicing good technique is helpful like 'leaning into the hill' to help your body carry itself forward.
Many hills types are out there and if you haven't thought about it before, going on foot up a few will freshen your perspective; the main two are long and short. Short usually have a high incline. Long can go on for a while with usually gradual incline, for example we had one hill I ran in college, that was well over a mile long, it was definitely a mind game. You could also sign up for the Mt Washington Road Race, which has plenty of long and short, but no downhill. If you do find yourself on a long hill, I find it best to look at your toes and find a rhythm to reel in the top. I personally like rolling hills best, because they're close together and you get plenty of downhill for your efforts. After you've gone down the first you feel like you've got momentum for the second...at least at the beginning. I haven't found a lot of great rolling hill places, it's mostly been in rural areas. (If anyone finds any in Eastern Mass please let me know!)
Calorie burn can be one of your main reasons for hill running, it simply burns more calories. Going up an incline increases your heart rate and in turn increases how many calories you burn for the same distance and period without it. I like the extra calorie burn and I simply like doing hills because it gives you something to physically scale. It is right there and it feels good to put in hopefully a few minutes of effort to come down the other side. It feels great to be 'over the hump' and rolling on down the other side.