"helpful for you" or "helpful to you"
Solution 1:
"Helpful to you" is correct if you only mean that something is helpful to somebody. It really depends on the context.
Dictionaries give these examples:
1) helpful to do something
----It's very helpful to bring a dictionary in my English class.
2) helpful for/in doing something
----Reading a lot of books is helpful for writing your own books.
3) helpful for someone to do something
----It's helpful for me to take a bus instead of the subway.
4) helpful to someone
----The movie, "Frozen," is helpful to children because it gives true love another meaning.
I hope this will help you. Good day! :)