If you want users to take part in trainings you organize, you will have to go through a few easy steps.
1. In Manage/Manage trainings use the "New training" button to create a training.
2. When the training is created, go to the "Dates" tab and create at least one date for the training, using the "New date" button.
3. Now you have to choose users that will be able to participate in the training. Just go to the "Assignments" tab and click the "Add" button.
4. Last step is publishing the training - after publication you won't be able to edit it and it will become visible to assigned users. To do that, go back to the "Properties" tab and click "Publish".