Another source of info is
http://www.flylow-flyfast.co.uk/
If this is your first time out taking photo's of low flight jet, the best advice is forget about spot metering, that will only confuse matters. And not sure it really works for the conditions in the Mach Loop anyway (light, shadow, shade) on a 600mph aircraft change so quickly its something you can worry about on subsequent trips, if you really need to anyway (I don't bother, plus several other friends who are out on the hills every week don't do either) and have got some great shots.
What you want from your first trip is to bag an aircraft, so my tips are:
AISERVO, single point focus (if you confident enough) or all switch on, as there's nothing between you and aircraft to distract focus points.
Shutter speeds 1/1000 sec or 1/1250 sec ball park for the jets, props, which will be TUC's 1/400 sec Herc 1/250 - 320.
Light conditions will be very important, you can't guarantee the weather in the Loop, so to achieve these type of shutter speed can be very challenging at time (or near impossible), increase you ISO (depending on camera, Max for non 1D series 400) and think about using + or - exposure compensation, maybe if you understand what it does (check manual). The Histogram is a very important tool, this will let you whether you're under or over exposing your images
It will also depend on your lens you have, as this will also effect the shutter speeds you can achieve in the light conditions. Minimum focal length for lens at all locations on the Loop is 300mm.
Panning Technique, pickup the aircraft early, track with it, keeping in focus and smoothly panning, when aircraft starts to fill 1/2 to 2/3 rd's screen start to think about taking a burst, 1, 2-3 shots, refocus to allow camera to catch up and then another burst. Machine gun approach will fill not get you good images, but will fill up your buffer and the delete image button on the camera will get some good use.
Cad West not good in the Morning because of the sun, So you could start at Cad East, drive up farmers track most of the way. The Bwlch shelves or Exit are good all day, Corris Corner, again in the morning, but midday sun in wrong position, so move to Cad West.
Hope this helps
Peter