While Nick Offerman has said that he admires many positive qualities of his Ron Swanson character (especially his work ethic and intolerance of people who lie or are lazy), he has also said that fans often wrongly assume he shares all of Ron's beliefs.
When Amy Poehler first visits Tammy at the library, if you look closely at the bookshelf to the left of Amy, at 5 minutes 17 seconds in, you'll see a book entitled "Sperm Suicide."
The scene with the diner called Frank's Restaurant is the same restaurant used in the movie Larry Crowne (2011).