I guess I wanted to start over and rephrase my first response, I have given it more thought. Wow what a job this can be, kick back and get ready for some Fun.
First do you have to sell? I started by getting a box of Silverplated flatware, and found so much fun that my wall are filled, but I have had a blast. Go through them carefully, Find out what you have. Some porcelain can yield more money then replacements .com will quote and most will be lots less. Not to down play replacement, it is a great site, just take that with a grain of salt. Get a couple of books if necessary and take each plate and spend a hour maybe two. Get maker history and possible year etc. anything you can learn about it.
Mediocre and low value ones, yea EBay them, but when you find that really nice one. Ask yourself do you have to sell it yet? With the state of the economy consider that right now it is a buyer market. Sell for porcelain still is good but only if you offer them a deal, and post it just right. Good pics, History, and etc. Get a good price in your head what it is worth, take a couple bucks off and you will make a bit. However if you wait until say around Christmas and sell, More will battle for you item. True value of any item is what 2 people are will to pay, not one, that is a bargin. If you can wait a bit do it, it will pay off.
Now for the really good ones, especially the one you like. Keep them and hang them up. Now what will happen is after you have gone through all those plates and have gain knowledge and begin to love the plates on your wall. You will then find yourself wandering the Thrift stores and finding that $20.00 that is only $2.00, you take it home, post it, make a couple of bucks. Won't replace your day job. But it can be a wonderful sell paying hobby, But then soon you will find even more wonderful plate upon your wall.
In my opinion that is what I would do with the wonderful collection of Plates. Enjoy I wish you the best with it.