In lunar photography, the Looney 11 rule is a method of estimating correct exposures. For daylight photography, there is a similar rule called the Sunny 16 rule.
The basic rule is, set the aperture to f/11 and shutter speed to the reciprocal of the ISO.
- With ISO 100 setting in the camera, set the aperture to f/11 and the shutter speed to 1/100 or 1/125 second (on some cameras 1/125 second setting is nearest to 1/100 second).
- With ISO 200 setting and aperture at f/11, set shutter speed to 1/200 or 1/250.
- With ISO 400 setting and aperture at f/11, set shutter speed to 1/400 or 1/500.
This is in full manual with the 1D Mk IV and a Tamron 600mm lens set to f11. You may need to do some tweaks so make sure you bracket.
A couple other tips... on the night "of" the official full moon, the moon will rise on the eastern horizon at the same time that the sun is setting on the western horizon. By the time the moon is high enough to be above trees and buildings, the sky is mostly be black.
If, however, you photograph the moon on the night BEFORE the official full moon, the moon will rise approximately an hour earlier. This gives the moon enough time to rise above trees and buildings for landscape/cityscape shots of the moon before the sky is too dark. As a result, you can get a dusky blue sky with enough light to illuminate foreground objects of interest.
The angular dimensions of the field of view of your lens at 250mm is 5.2º wide by 3.4º tall. I used the angular field of view calculator on this page to figure that out: http://www.tawbaware.com/maxlyons/calc.htm (the calculation needs to know the "crop factor" of your sensor as well as the focal length of the lens to figure that out. Your camera has a 1.6 crop-factor -- so you would always enter 1.6 in that box -- treat that as a constant.)
The moon's angular width from edge to edge is roughly 1/2º. (about 30 arc-minutes). During a perigee moon, it's slightly larger... about 33 arc-minutes. It's apparent size does vary slightly between apogee and perigee... just not by much. When the full moon occurs at perigee, people refer to it as a "super moon" (super-moon is not an astronomy term). To paraphrase Neil DeGrasse Tyson... that's "super" if you think getting an 11" diameter pizza when you were expecting a 10" diameter pizza qualifies it as a "super pizza".
This means the moon is somewhere around 1/6th to 1/7th the height of the field of view and about 1/10th of the width.
The angular size of the moon will not change whether you walk closer or farther. What WILL change is the angular size of foreground objects of interest (landscapes and cityscapes).
Suppose I want to photograph the moon rising above a cityscape... if I am very far away from the cityscape, the buildings will seem smaller... but the moon will appear to be the same size to me, but will appear to be getting larger in comparison to the buildings. If I now use a very long focal length lens, I can get a shot that makes it appear that I was not very far away from the buildings (they'll seem large) and yet the moon will appear to be enormously large in comparison.
Follow the Loony 11 rule above. You can use different f-stops other than f/11, but f/11 is the only f-stop at which the simple rule of shutter speed being the inverse of the ISO setting is true.
Also, if you photograph the moon when it is not full (see the Gibbous moon below) then the image reveals considerable texture of mountains and valleys on the moon because the light is coming from the side. This gives the moon less "flat" and more 3-dimensional look.
Thanks for the rules eBiggs. I'm going to try them out soon. Here are a couple of shots from an 18-55 Canon lens. 
