Dick Friel has posted an article on how to train for climbing if you don't have any hills:

https://www.active.com/story.cfm?story_id=12755

He describes two workouts. The first one builds leg strength, the second one builds leg endurance.

I suggest one modification to the workouts: if you're doing them on a trainer, raise the front wheel by 3-4 inches to simulate the bike orientation when climbing.

One further comment: the strength workout will certainly help, but standing start sprints are more effective at building leg strength.

Training in florida to do rides with lots of climbing is difficult. What worked for me was a lot of LT threshold intervals. Essentially power is power, whether it's 23mph into a headwin or 8mph up an 8% grade. Worked out pretty well. (10th place Brasston Bald century, Silver Medal L'Etape de Tour). Biggest thing I found training on the flats didn't train was my back, so I added some core exercises which helped that.

As for raising the wheel on the trainer, my first coach reccomended it, my new coach sort of scoffed at it, so I don't bother with it anymore.

I've found the Chris Carmichael climbing interval DVD works pretty well.