Kaesora Library Swarming Guide
Kaesora Library is one of the most popular swarming locations in the entire game. It's best between the levels of 92 - 95 but you can stay here until 99. Once you hit 100 though so many of the mobs go green there is far too small of a chance of you getting Mortal Coil procs to swarm here with even a modicum of success. You'll quickly fall in love with Kaesora Library because of how many mobs span this giant camp. Though, you'll quickly learn that the biggest threat to your life here is the named mobs.
There are quite a few and if you see one at a time when you're not mid pull, you'll want to go out of your way and kill it. Usually getting one in a pull is ok and you'll survive (unless it's the named that stuns, then no... you're dead...) But it's still a danger to your life that you don't want to risk if you don't have too. Just be very careful when you're around them.
As far as pulling this place goes, there are many different options available. I usually pull the whole top ring and then I pull the pit area and the two hallways that wrap around it. Then from there I pull the whole sewer area until the super large throne room down in the sewers. And then sometimes I continue with pulling that area too but that depends on if mobs are back up in the upper areas yet. It's pretty easy once you get used to it and you'll also have to get used to not leashing mobs when doing the really long pull through the sewers down to the large throne room area.
Here is a map of the area you'll be handling in Kaesora Library.
((Unfinished - swarming got nerfed in 2014))