Three quick questions to start you off on:
- How often do you check your website hosting account / server to make sure its ticking over correctly?
- How often do you check the bandwidth used by your site?
- Do any notification emails go to someone who understands them?
Unless you happen to have your own server hosted in a data centre and are hopping on and off it most days like some poor sys admins do, the likely answers are: Not very often, Not very often, No idea.