I am only too happy to answer the questions you post here.

This is a phrase typically used when a person is happy to do work which others think they might not enjoy. "I'm only too happy to give you some example sentences." "He was only too happy to move to China for work." "We are only too happy to take care of your dog for the weekend." I prefer to use "more than happy to" because it sounds more sincere, but to each their own :)