Source for YARP are available from https://github.com/robotology/yarp.
Installing YARP is easy it can be done from sources or directly from binary packages. We provide in the links below detailed installation instructions for all systems.
Installing the software is easy but if you are really in a rush you can download a virtual machine that contains all the software pre-installed: https://github.com/robotology/vagrant-icub
After your are done installing YARP you can proceed with the following link: Check your installation.