Database Software

I am just getting started with Workflow and using the Workflow Builder and so far it all makes sense but I am slightly confused about how Workflows are triggered. Also, I see that Oracle comes with a number of seeded workflows but I can't find any that will accomplish what I want.

So I guess my first questions is:
Are there any seeded workflows that deal specifically with Benefits (OAB)? For example, if a user triggers any life events (gets married/divorced, has a child, etc) I would like to send out a notification to the benefits group.

Assuming that there are not any workflows to accomplish this I think I know enough to create my own. Lets say I create my own workflow that sends a notification to the Benefits group anytime a life event gets triggered. What do I need to do to fire off the Workflow? In my scenario, the Workflow would need to get fired off both in Employee Self-Service (if the employee changed marital status for example) and in the HR application (if a HR person changed this information at the employees request). I guess my question is: How do I fire off the workflow? Do I need to create a trigger on the table that contains this information that calls the workflow?

Any help appreciated
Thanks
Jason Hochwender