What is virgin vinyl? Is it better

What is "virgin vinyl"? Is it better? And what are 180g records? Are 180g records always virgin vinyl? Are these good predictors of whether the used LP I just brought home will have crackles and pops or not?
Virgin vinyl is the highest grade, pure vinyl with very low impurities used in making vinyl records. It usually sounds quieter with less clicks and pops than standard vinyl. A 180g record is one that has 180 grams of vinyl used for its pressing. Usually 180g records are pressed with high quality virgin vinyl and are thicker than standard LP pressings.
Record companies used to (still?) recycle product that didn't sell. They'd get records back from their distributors, stores, wherever, punchout the label area and melt them down for reuse. Sometimes the labels aren't perfectly centered and paper gets into the mix (I've seen paper in records I've bought). Needless to say, paper doesn't have a very wide frquency response or dynamic range... Long live CD's !!!!
Matt, Audiophile pressings are often 180 gram but most typical used records are not. Whether or not the 180 gram record will sound better on your rig depends on how you set the VTA on your arm/cartridge. If most of your collection is on typical vinyl, the kind of records you are most likely going to find in the used bins, you will want you VTA set for that thickness - but then when you play a 180 gram disc it won't sound up to its potential without resetting the VTA. If the VTA setting is unimportant to you, or resetting the VTA is too much of a problem (it usually is) then it is likely the difference gained in 180 gram records will not be important either.
How do I set the VTA? Is there a good link (maybe with pictures) on how to set up/configure everything turntable related?

You mean to say audiophiles playing 180g lp's and regular lp's are resetting their turntable each time?
Matt, this is a can of worm's not often discussed but is recognized by serious vinylphiles. There are turntables where the VTA can be changed on the fly to accomodate the angle of the cutter head on the lathe that cut the disc in the first place (not always the same, but often known by true vinyl experts) as well as the thickness of the vinyl. Some like to use the adjustment on the fly just to fine tune the sound. VTA changes with the stylus forces selected as well as the thickness of the disc. The angle of the stylus on cartridges is not standard. And the proper VTA does make a real difference to folks who have the listening skill to hear it. It is most easily discerned by differences in tone and soundstage image. Most arms allow for static adjustment, but because it is complex and equipment dependent, some turntable/arm manufacturers (well known ones) don't even provide for it at all - you just have to be sure to get a cartridge, that is the right heighth and has the proper stylus angle to begin with to achieve what in effect is a good sound most of the time. If this subject really interests you i would chase down some literature on it and read up.
Long Live CD's ?????

CD's were not even born in my heart.