You can get all of them easily if you know where they are. They don't have anything to do with a quest really. I never went out looking for them. I just happened to stumble upon them. I can't remember where they all are off hand but I know one is in the lighthouse up near Windhelm or Winterhold. Another is in the basemant of one of the Orc strongholds (trap door in the floor). There are only 5 of them.
Anyway, they can all be reached at any time.
I just got the tourch bug... did the quest that start's in their. ( because I wanted to ) I may "chase" down the other's, just because.
I have two... problem is I can't "put" them down they fall where ever when I drop them. I kick them around my house all the time... best darn jars I've ever seen... unbreakable it appears... WEWT !! MuzzaFuzza
Yes they do fall where you drop them, then you pick them up and put them where you want them. The jar's really don't like bein rightside up, but otherwise are not really that hard to place.
I only know how on 360, ps3 may be similar, but press "A" button ( don't tap ), if it's still there, just lift it to where you want it. Then press "A" again. ( make sure not to hold or press twice )
Like I said getting them in the up-right position is harder than picking them up. You may have to do it more than once as thing's like to jump off of where you put them. My Grey Fox bust is a constant pick-up and put back. "A" is the take button, so I'm sure ps3 is probably the same ( different button). I have no clue on pc...but think maybe the "E"??? key?