Recipes often suggest you salt the eggplant prior to cooking. This will draw out some moisture as well as some bitterness that some eggplants have. When excess moisture is removed the eggplant won't act like a sponge when you fry it in oil.
Peel the eggplant if the recipe calls for it and slice it to the required thickness. Place slices in a colander and put it all in a large bowl to collect the water. Sprinkle liberally with kosher salt (f you have it) and let the eggplant rest for about 20 minutes until the salt draws out some moisture. Rinse the eggplant thoroughly , let drain and blot dry. You're ready to go.