"How to Run a Personal Record: Cover the Ground in Front of You Faster Than Ever Before," by Dave Kuehls, pg. 14 - 15.
One of the two cornerstone workouts for the Strength Work phase, hills are run on Tuesdays during the week (Note: Wednesdays in my case because I pushed the schedule by one day so that I have two workouts on the weekend, hence why I have Mondays off.) The key, of course, is finding the right hill. Look for one about 100-200 meters long and about the grade of a highway exit ramp, something challenging but not severe. Footing is also important, so some trails may be off limits. Traffic may be another impediment, so some roads may not be ideal. Scout out possible hill work locations while still in your Road Work phase, so as not to be stuck when hill work comes upon you and you are without an adequate hill.
For hill work, after a warm-up jog, you'll run several times up a hill, then follow that up with a cool-down jog. On the hills, you should shorten your stride, leaning into the hill and dropping your arms so that they pump near the waist. Start conservative at the bottom of the hill and try to maintain pace the entire way up (this is Strength Work, not speed). Always "run through the hill." That is, as you approach the crest, don't slow down, but maintain your cadence even as the hill levels out. On the way down, run slowly and carefully, as injury is more likely to occur going down a hill than going up. At the bottom, jog for a minute or two before beginning the next hill climb.