Grading system

SS / Still Sealed

Never opened. Flawless, with no damage whatsoever. Might be Sealed or Not dependend on the manufacturer.

NM / Near Mint

Vinyl: nearly perfect. A very minor scuff and very little else can appear on the vinyl. This will most likely have occurred during packaging, or removing the record from the inner sleeve but had been handled with extreme care.
Cover: the cover looks as close to perfect with only minor signs of wear and or age.

EX / Excellent

Vinyl: an excellent condition for vinyl will allow minor scuffs which are visible but only slightly.
Cover: Artwork looks as close to perfect as can be. Some impression to the cover (minor outer ring wear) but no ink wear! Some slight creases to the corners, but not wrinkled and obtrusive to the eye.

VG+ / Very Good+

Vinyl: may have scuff marks and signs of some wear but will still play almost perfectly throughout, with only "barely detectable" crackles or pops. A slight noise at the begining is allowable, but the remainder must be nearly flawless. Definitely no scratches or gouges that a touch with a dry finger can feel. 
Cover: may only have the slightest signs of normal wear.

VG / Very Good

Vinyl: may crackle, pop or make other annoying noises, but only occasionally,never continuously, and not more loudly than the music being listened to
Cover: normal used cover wear such as ring wear and split seams. If there is abnormal damage such as tears or markings, it is described in comments attached to the item.

G / Good

Vinyl: may have continuous low level crackles, pops, etc... but not so loud as to make the music completely unlistenable or unenjoyable to the casual listener. Might also have "nasty little scratch" causing popping on one or two more songs, with the rest of record playing fine.
Cover: may have any kind of wears and tears but is not torn. It may have seam splits, but not repaired with anything else than scotch tape.

F / Fair

Vinyl: mostly quiet noisy the whole way through, might have heavy scratches and might even skip.
Cover: might be torn, taped and written on but not all of it. 

P / Poor

Vinyl: only one or two songs on the whole album are playable.
Cover: might be torn, taped and written on. 

none / missing

is missing