I will be heading to guitar center tomorrow and I need to know what to look for in testing guitars/amps/effects. I plan on testing an Ibanez RG4EXQM1, RG3EXQM1, RG5EX, and maybe a Schecter or two.

For amps a Vox Classic Ac15CC1, Epiphone Blues Custom 30, a Palomino V16 and a Peavey Classic 30.

For effects, a EHX Metal Muff, Big Muff Pi, and a Digitech Bad Money.

Any advice on what to look for when testing, or any advice on any of the items listed above, please list.

Help much appreciated.
Guitars - Whichever feels best to you. Do you like the feel of the neck? Do you like the contour on the body? Do you really need a guitar with a floating trem? Do you like the H/S/H pickup configuration over H/H? The obvious, check for flaws.

Amps - Use your ears, not your eyes.

Pedals - Seems like you're looking to go tube. Judging by the amps you've listed, I'm assuming you play rock or blues. So, spend more time trying out overdrive pedals rather than thin, harsh distortion pedals. Give the Big Muff a try though, popular pedal with a different sound.