This was my bike hill workout yesterday. Find a hill that is about 3-4% grade - you are not looking for something insanely steep, just a steady climb. Then do intervals of 6 minutes at Olympic distance effort. Take four minutes between to ride back down, drink a little and start over. I did 12 of them, but you could easily start with five. Try to stay seated (I am horrible at this).
The workout is a bit repetitive (read: boring), but it will make you strong...
This workout can be done on a hilly loop route, or you can do repeats up a single hill. I prefer a hilly route, as I tend to like change in scenery. Each time you get to a hill try to sprint up it as if you are at the end of an Olympic distance race. Run hard over the top (it's so tempting to slow down near the top) and recover on the flat or downhill. The rest of the run is just cruising along. Try to aim for a minimum of seven hills.
Happy hilly /\/\/\/\ training!