Fonts In Use is an delightful site for finding.. well, fonts in use. You can filter on topics, formats and typefaces, which makes it ideal if you are looking for inspiration, or something specific.
Each example has the hierarchy of typefaces used for the given piece of media, which has helped me get an idea on which typefaces go well with others.
Be warned that prices are not listed, so I’d check that out early before becoming too attached to a typeface. I’ve been surprised at how affordable some of the fonts used by brands are though.
Not much else to say on it really. I just think it’s neat.
Also, I have no idea when to use “font” and when to use “typeface”. There is no way to find out.