Set up a centralized location for your packages, and either robo-copy them down (your IT should be able to handle this), or have everyone path to the network location for their package directory.
Also be sure to document what package each custom node is from, and what packages (including version) are in use for every graph. The Monocle view extension is great for this part.
In Dynamo Under Settings I believe is “Manage Package Paths” which is where you can set up a network location as @jacob.small said. It is very helpful to keep packages up to date as you create content.