Announcement of the training sessions can be done with notices. But if you want no one to miss out the announcement then notifying through letters is the best.
On ______________ (Date) we will conduct training sessions on the use of our new computer network, which covers the complete list of its latest developed factors.
The sessions will be conducted in the ___________ (Place) room at ____________ (Time).
All the employees are expected to attend the session. Please consult your supervisor to select the time that suits you best. Also notify us of your plans previously. We look forward to seeing you there.