Making Madeleines!

So here I am making something that I have never made before which contains directions for things I do not know how to do and ingredients that seem foreign to me...
Ingredients:
3 eggs
(What in the world are eggs?! Jk)
1/2 cup of caster sugar... Meaning superfine sugar.
(Hint: blend regular sugar)
1 1/4 cups all-purpose flour
3 1/2 oz. unsalted butter
(Thank goodness I accidentally bought some a while back...)
Grated zest of 1 lemon and 1 orange
(Umm.... Ok, whatever that means...)

Preheat oven to 400*F
Brush the Madeleine tray with melted butter then coat with flour. Shake the extra flour out of tray.
Whisk eggs and sugar until the whisk leaves a trail when lifted.
Fold in flour. Then the melted butter and the zest, with zest!!
Spoon into tray and bake for about 12 min if the madeleines are big and 7 if small.
Tadahhhhh! If I can do it you can too:)