honrocks

I like lydia but Serana is so much much better. =] She actually can build a relationship with dovalkin depending on how you talk to her.

I may have a theory on why this quest won't start for you. I had the same problem before. Do you by any chance have the mod Better Whiterun 7k under construction? This mod does make hitting the books quest not start. If you don't you may want to try re-installing skyrim if you tried the all the Console commands methods already.

Did you by any chance have Better Whiterun 7k installed? If you did that might be the problem because when i removed the mod completely and started a new save game I did not run into the thief near riverwood.