You can usually tell the quality and type of weed by certain characteristics associated with it.

Does it have alot of crystals? (white specks on leafs n bud) If so, its pretty good quality stuff.

Does it have a smell? I tend to find the stronger/danker the smell, the better the quality.

How dense is it? If its very dense, try to break off less then normal and see how that works out.

Never forget there are as many strains of weed out there as there are opinions, if it has a distinct smell thats very pungent, alot of crystals and it has a unique look (white hairs, blue bud etc.) its probably some good stuff.