| Daisy, its nice that you were able to keep them going through winter in as good a fashion that you did....but now you wish to get them ready to go outside .....about mid May....when your other annuals are planted. I will try not to step on what Janet has outlined....but
if I may suggest ....
take your geranium to a well-newspapered table, there unpot your geranium and cut it back...by a third....back to about 4 - 5 inches high.
Clean off all leaves, cut back all broken or otherwise damaged branches. Clean all soil away from the roots.
Inspect the roots for any sign of damage....and cut back if necessary. Then, with a clean pot (I like clay), to which you put into the bottom something to keep the soil away from the drainage holes, (I use clay shards) put some FRESH potting soil/mix in....make a hole in the center, and put your plant it...firm it up, take to the sunniest window you have.
(north though will not do)...there water your plant to drainage. Let the plant drain ...and let the plant sit in that drainage water no longer than 15 - 20 minutes....then dump it.
Now....no more watering until the plant begins to produce new leaves.
Then, water as necessary and do not fertilize until new leaves begin to form....then at 1/2 rate until the leaves are well along.
Will take maybe 2 weeks....less or more. Water always to drainage, letting it dry down a bit...never let it go dry. Maybe, in 5 or 6 weeks, you might get flower buds forming...in any case, they will form sooner or later. That's it...that's all there's to it. A couple weeks before you figure they can outside in their own pot....take to the garage and then outside to acclimate them....taking them back indoors at night.
Back outside during daylight.
This acclimates them to the outside temperatures....better to withstand a night that goes down when you do put them outside to stay. Then its just a matter of enjoying them through the season and not letting them be touched by frost later in the fall.
Then, back out again in '08...'09....'10.....'20....'30.. | 
