Eggplant

So I planted a "Black Magic" eggplant that I bought as a seedling from my local garden center. I've never grow eggplant before, neither as an adult or as a child, so I thought it would be an interesting experiment, seeing as how I adore eggplant parmigiana. I learned a few things this year in doing so (eggplants are like peppers, wait to plant them until it's warmer - I planted mine too early and it did almost nothing for an entire month before finally taking off and growing). However, I now have a dilemma trying to figure out when to pick them. Since I don't have a seed packet, I don't know how big they'll get. I tried Googling it, but mostly just get a list of cultivars and general eggplant knowledge. One helpful thing was that a ripe eggplant should have some "give" when pressed but no indentation should remain. However, something else I found from a seed website says harvest when the size of your fist, which seems like a darn small eggplant. So I think we're going to harvest one on Friday morning before we leave town and see how it goes. As far as growing eggplant, once I figure out when to pick them, it's been great. I think I'll get at least 8 off this one plant, and it's been very easy to grow - no disease or pest problems.