Which training database?
If you meant the *sample* database "NorthWind", it is not a training
database and there is no "training manual" for download AFAIK. Microsoft do
use this database in numerous examples in their documentations and Knowledge
Base articles but that are not in one place.
If you want to use the NorthWind database as the training database, you
should get the book "Using Access {YourVersion}" by Roger Jennings as this
book follows the sample database "NorthWind" fairly closely.