My azaleas bloom heavily in May.  Mine are all evergreen, although there are deciduous species.  I keep my azaleas closely cropped, usually trimming them four times a year.  Many so-called "experts" claim that using hedge trimmers will result in shrubs that don't get any flowers.  I'll let my pictures speak for themselves.  Azaleas like an acid soil, but not as acidic as many people think.  If you live in the east, your soil is probably already suitable for growing azaleas, unless you're planting them where a lawn once grew.  The use of special azalea fertilizers is a waste of money - any ordinary garden fertilizer will do.  Although they like a soil rich in humus, mine are growing in rock-hard foundation back-fill.  I've added loads of compost to my azalea beds over the years in an effort to improve the soil.  You should remove any dead growth you may find.  New growth will soon appear to fill in any empty spots.