Adding Exceptions on Adblock Plus?

[OckhamsFolly]

Like all right-thinking individuals, I hate being inundated with ads while surfing the internet, and to that end, I've installed Adblock on my tablet. However, as a conscientious consumer, I like to add exceptions to sites I regularly visit so that they have a chance to get their advertising dollars and can continue to provide content at no direct charge. Unfortunately, I can't figure out how to add an exception on my Nexus 7. Can anybody enlighten me?