Summer plants: plant out after last frost in April or May.  Eggplant is less tolerant to cold than tomato plants.  Wait to plant, or cover when nights drop below 50 degrees.
 
Eggplant plants are sold in individual 3.5" biodegradable peat pots.  Peat pots can be planted in the ground to avoid root disturbance, but I recommend tearing strips down the side and bottom of the pot to allow roots to grow quickly out into soil.
 
Space plants 18"-24" apart.  Support is strongly recommended.  
 
Variety information:
Ping Tung Long: Asian variety with long, slender, light purple fruits.  We prefer Asian eggplant for a couple of reasons: they tolerate our pests and climate much better than European varieties, and they are easier to use in the kitchen.  The stem end is trimmed off in one quick slice, leaving nearly all of the fruit usable.
Michal: European variety with beautiful plump, deep purple (almost black) fruits.  While European varieties grow less abundantly than Asian eggplant, we always grow some European for both its beauty and because it's simply better for several classic eggplant dishes, including eggplant parmesan.