It's really hard to guess FG- there are so many factors involved- grain bill, yeast attenuation, extract fermentability, yeast health etc etc. I'm going to guess it'll finish just under 1.020, say 1.018 or 1.019. I'm only saying that as long as you promise not to freak out if I'm wrong.
If you want it to taste as good as possible and ferment out completely, be sure to pitch the right number of cells (either make a starter with liquid or rehydrate your dry yeast), aerate your wort appropriately (read: A LOT) and control your fermentation temperatures.
I can't be arsed to keep up this list of what's in the fermenters, but hey, check out the cool brewery I own!
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