In our experience eggplants are easy to grow... the plant, that is. Getting a worthwhile number of fruits is another matter, and one we're still working on.
Start seeds indoors, using a heating mat to warm temperatures to 80-90F. Transplant 2 feet apart once nighttime temperatures are consistently above 50. Harvest eggplants with a sharp knife as soon as they're ripe, while still glossy and firm. Harvesting the first fruits when they're still small encourages more to grow.