The default location of the database is now:
<current_user's_home_directory>/Library/Application Support/Organise/organisedatabase
v5 allows you to choose a different location for your database which allows more than one user or more than one computer to access the same database. It also allows you to switch between multiple databases. This is a pro option and requires a licence key to unlock.
You are strongly recommended to take a backup copy of this database every so often by copying the file onto another drive, cd or memory stick. If you use Time Machine then this is taken care of.
The ability to import a version 1 database has been removed in v5