Nathan Bransford needs no introduction. His is a very popular blog. It also has a forum where you can share and gain a lot through interacting with many others. In this 2008 post, he writes of what he calls a basic step Finding a Literary Agent.  I am sure you will find this as useful as I did.

On reflection, a mistake many eager seekers of agents make is to try for many agents at one time. Categorising them based on their handling your type of work and getting after them on the basis of these priorities seems to make a lot of sense.

So if it isn’t too late to do so, check out your short list of literary agents and decide who should be in your ” A” list.