I'm trying to recall the name of a book which follows the cast of a fantasy story when no one is reading. The characters in the book act out the story much like actors on a stage, and when someone is reading the story the characters can look up and see them. When the book is closed everyone is 'off duty'. The second book in the series involves the book being uploaded to the internet.
"The Great Good Thing" by Roderick Townley
Sylvie had an amazing life, but she didn't get to live it very often.
Sylvie has been a twelve-year-old princess for more than eighty years, ever since the book she lives in was first printed. She's the heroine, and her story is exciting -- but that's the trouble. Her story is always exciting in the same way. Sylvie longs to get away and explore the world outside the confines of her book.
When she breaks the cardinal rule of all storybook characters and looks up at the Reader, Sylvie begins a journey that not even she could have anticipated. And what she accomplishes goes beyond any great good thing she could have imagined...
The second book Into the Labyrinth's description is:
What a relief when the old storybook is republished and the characters who live inside it suddenly discover they have Readers again -- lots of Readers! Princess Sylvie finds herself rushing to get to her place whenever a new Reader -- whether in Boston or Bangkok -- opens the book. Her mother, the queen, is especially frazzled when the popular story is loaded onto the Web: a weightless, "virtual" world of unforeseen challenges.
The "Thursday Next" series by Jasper Fforde.
The series takes place in a "book world" where the "actors" live. Thursday Next is a detective with the ability to travel between the book world and the real world. The first book is The Eyre Affair and is followed by Lost in a Good Book, although I was not able to find the internet thing you mentioned. The series also takes place in an alt history setting if that helps.