Bilbo is very well known from the book The Hobbit-but then also well known in the lotr, as this is after The Hobbit. Bilbo wrote a book about his journey's it is called 'There and back again'-as we see in the film.
He got along with Elves as did Frodo, but also had friends who he met in the Hobbit, who were Dwarves.
We find out from the film that is his 111th birthday, and because of having the ring for 60 years he has not aged as Gandalf comments on in the film, but Bilbo tells Gandalf how he feels thin and stretched.
Bilbo wasn't actually the first Hobbit to have the ring-it was Deagol, who was a friend of Smeagols.
more info soon
