First, delete the folder we created in the previous step under sourcemods/ (if you have no other mods installed, this directory should be empty now). It would get tedious to copy over the mod directory everytime we build our binaries so instead we can symlink our mod_ folder so that it is always up to date. Every time you rebuild your binaries you will need to make sure to copy them to your mod directory under sourcemods/ before you launch your mod. Restart steam after this step and you will find your mod listed in your steam library.
This folder contains all the necessary assets, binaries and scripts for your mod, the most important being gameinfo.txt, bin/client.dll and bin/server.dll. The source 2013 sdk provides some base files for you in the game/ directory. In order to launch your mod then the necessary files need to be created in your steamapps folder.