Is it correct to say "I recommend this book for you"?
Oxford Advanced Learner's dictionary says: recommend to someone for/as something, but you can often see the above version in texts.
"For" means the person who will ultimately use it.
"To" is the person who receives the recommendation.
Lately I have been recommending a particular book TO my friends FOR their children. (It's The Mysterious Benedict Society, in case you have any children between 8 and 12. I highly recommend this book for children of that age.)
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.