Question: Hello,

I'd like to hear your opinion for ergodic theory books which would suit a beginner (with background in measure theory, real analysis and topological groups). I am looking for something well structured, well motivated, and perhaps with application to other fields.

any such book exists?

I tried a book by nadkarni, and could not read through it, seemed to concise to me, and tried the book by Petersen which I felt was accessible but didn't follow a clear path, jumping from subject to subject with lots of different object or properties.

What are your recommendations on the subject?

Answer: 
For me the standard text is Peter Walters, "[An Introduction to Ergodic Theory](http://books.google.ca/books?id=eCoufOp7ONMC&lpg=PP1&dq=peter%2520walters%2520ergodic%2520theory&pg=PP1#v=onepage&q&f=false)", Springer Graduate Texts in Mathematics.
Personally, I like Mañe's book Teoría Ergódica. I do think it's a classical book full of exercises. On the other hand the book has loads of mistakes, which makes it interesting to read, you realise that you are understanding everything when you spot the mistakes. As far as I know, both versions (English and Portuguese) are sold out.