It's just a hill, get over it!
1. Don't fear the climb. Biking is such a mental sport. Part of getting up the hill is willing yourself to get up there. Think positive!
2. Don't start out too hard. This is a common mistake lots of cyclists make. Taking the "the faster I go, the faster it's over" attitude can work for short, punchy hills but for longer climbs it does not work. You'll burn too many matches too soon and you'll regret it halfway up the hill when your buddies come spinning by you.
3. Keep your hands on top of your bars or hoods as long as it's safe to do so. This keeps your chest open and allows you to breathe better.
4. Belly breathe. Open your diaphragm.
5. Relax. No need for white knuckles, just keep a light grip on your bars. Make sure your shoulders are relaxed - they should not be touching
6. Don't rock your upper body back and forth unless you are out of the saddle. You should be the proverbial swimming duck: quiet on top with all movement coming from your legs only.
7. Spin. Spin. Spin. Keep your pedal cadence high. While this requires more work from your cardiovascular system, it helps save your legs. Climbing out of the saddle expends a lot of energy so try to stay seated until the hill gets too steep to do so. Use your gears to keep a steady cadence.
8. Watch the best climbers in your group. The best climbers are not only fast, they make it look easy because they are relaxed. Emulate their form.
9. Dress for the descend. You might get nice and toasty climbing up the hill but the descends are frigid. Dress in layers and zip up before you go down.
10. Enjoy the view. You just spent all that energy getting up the darn thing, you may as well take a moment to take in the view from the top!
A note on descending:
1. Stay in the drops when you're descending. This keeps your center of gravity lower, helps keep your weight back and allows you better access to your brakes
2. Whatever you do, do NOT slam your front brake! Also, don't brake in the turns when descending; brake just before the turns and pedal out of them. And when turning, keep your outside pedal down, and inside pedal up.