You can add events, including seminars, by going to Content -> Add content -> Event
An event can be classified as a Seminar by checking the appropriate box(es) under "Event Type" at the top of the edit form.
All published nodes of type Event that have a date of today or later will show up on the "All Events" page, and the five most current events will show in the Upcoming Events block on the home page. (We can show more or less than five, just ask your contact at BioCom.)
In addition, there are pages that will automatically list upcoming seminars of the two types:
Events that are taking place today or in the future that have one of these seminar categories checked will automatically appear on these pages.