Thinking about introducing ads. Should I inform my users via announcement?

window.document.getElementById(‘post-3845’).parentNode.className += ‘ adhesive_post’;My site is pretty small, and I’ve been reluctant to put ads on the site, simply because I think it will just annoy people and not earn me much. But, that has changed, and I have decided to put a few ads here and there (nothing too excessive).
Anyway, as a forum admin, I am trying to be extremely friendly and likeable, and one thing I strive to do is be completely upfront and honest about everything. Now, introducing ads, I want to know how some of you went about it. I’m not sure if I should tell them that ads are here, and the reason why (most of the money will be put into making the site better), or should I just do it.

Original post by dpatel304