http://www.gardens.com/flower-gardening/pruning-azaleas.html

There are also videos on YouTube

The best time to prune is right after the flowers fade. Next year's flowers set shortly after that.

Mature azaleas are hard to transplant and keep alive. They have shallow roots and do not like to be planted deep. They require a LOT of water, and do best with a drip on them for several days. Then a drip once a week( overnight) until established. That said, the smaller the bush, the better your transplant. I trim my azaleas right after blooming, but have to trim some branches again, as they hang over my walk. Do not trim them with shears, but cut back random branches about a foot deep throughout the shrub. New branches will start from the old stubs.make sure that the soil is acidic enough...if the leaves turn yellow, it needs an acidic fertilzer. Good luck!

Make SURE the roots are spread out over the most soil surface, not stuffed into a hole! Do not for any reason, ever, scratch the soil over the roots. They hate that! Do not scratch fertilizer into the soil, or put toomuch mulch over the roots!