There are two options where to store your checklists and templates.

Upload them directly to Stages if you would like to

• version and release them together with your processes
• have full change control through Stages

Store them in an external CM system like Sharepoint or SVN and use the Stages integrations to connect them with your processes if you

• want to be able to update them without issuing a new process version
• already manage them in a CM repository and you cannot change that location without breaking other processes

So at the end, it comes down to the level of governance for your checklists and templates and how frequently they change.