I can see why, being a native Spanish speaker, that you might think "I hope this help" is correct, but English only really uses the subjunctive for the verb "to be" - hence why "I hope this helps" is correct.
Thank you for the clarification. I am not sure about the subjunctive used only for verb "to be". Ex. ''It is important that she study more" I understand that is it more visible with verb "to be" but I think subjunctive applies for all verbs, pretty much.
That's a bit of a digression, so perhaps topic for a different thread.
Getting back to the original question, either sentence is acceptable (or both sentences are acceptable) and both are seen frequently, though I get the feeling that using "will help" has more of a suggestion of doubt than "helps". (I don't know why, it's just how it feels to me. I'm sure someone will come along to explain in depth - if they feel the need.)