I was reading some old posts about brushing simple syrups on cakes will make it very moist. It mentioned doing this on cakes you're pulling from the freezer. would I do this on a fresh cake? do i do it before icing it? is it ok if i'm using frosting and then fondant?

it mentioned various flavorings...would this be just extracts?

sorry so many questions. thanks

AYes, you can do it on fresh cakes as well, and you put it on each layer of cake before icing and filling. As far as flavoring goes; vanilla or nothing is my opinion. If it's chocolate cake you do not need any flavoring since the chocolate will hide the flavor anyway. If you add flavor, I don't think it matters if you use extract or e.g. vanilla bean, the syrup doesn't add that much flavor anyway.