I'm usually in AI Servo and Evaluative. I'm still a little unsure of the center-weighted average metering mode. Does anyone have a good explaination of this mode and a situation where I would want to use it?

meter reads from all metering zones and averages with bias towards the center zones.

That's a good mode to use when your subject is in the center of the frame and there's something bright towards the edges of the frame

I also find it to be the best mode for flash exposure with Canon's ETTL

I mostly use either evaluative or spot metering. Mostly AI Servo, with C.Fn 4 set to 1.

weddings? Single shot and CW..

<a href="http://www.cambridgeincolour.com/tutorials/camera-metering.htm">Metering tutorial</a>.

Focus mode is usually One Shot, but I use AI Servo if the subject is moving. Metering? I had to lookup what the symbols meant in the manual. That's probably my biggest weakness right now.

I visually make the correction if needed.

For evenly lit scenes, evaluative is fine.
For backlit scenes or other odds lighting scenarios, center weighted or partial.
Spot metering is for scoping dynamic range in a scene. Usually I don't do this. Normally I make a determination about what I want metered correctly in the scene, and let the rest blow out or go to black if it must.

AF usually has CF4 set to 1 to decouple AF from metering. It's a workflow thing. It doesn't need to be like that all the time, but changing it on and off will screw up a learned habit and I want to use it more often than not.

AF mode is single shot for things that don't move, and AiServo for stuff that does (1D is great with AiServo, but I don't trust it on the 5D and usually avoid it unless the subject is sufficiently large to always fall on one of the two AF points Canon saw fit to outfit me with!!!).

Focus points chosen will either be center point (common with the 5D), a selected point, or all points. It just depends on what kind of movement I'm shooting, whether I have to shoot without looking into the viewfinder (it happens), how close the subject is to me, lighting conditions, and the body I'm using.

I have a few shooting and custom banks...

General shooting:
- Center weighted or Matrix metering
- Aperture priority
- AF-C or AF-S
- Focus Lock Normal
- 51pt 3D Dynamic AF

Sports:
- Matrix metering
- Shutter Priority
- AF-C
- Focus Lock Short or Normal
- 9 or 21 pt Dynamic AF

Wildlife:
- Center weighted or spot metering (there are a few automatics I rely on..like for White Egrets, Snowy Egrets, Snow Owls and other white birds.."Spot Minus One" nails it every time)
- Manual exposure
- AF-C
- AF decoupled from the shutter release using the AF-On button
- Focus Lock short or off if shooting BiF's
- Single, 9pt or 21pt Dynamic depending on the subject
- Cable release

Macro:
- Center weighted or Spot metering
- Manual exposure
- Manual focus with the aid of focus rail and Katz Eye Focus screen
- Single point
- Exposure Delay, or Mirror Lock-up if needed
- Focus Lock Normal or Long
- Cable release