Question from an Adsense newbie.

[raymail]

I have a website that serves adsense advertisements. I read through the rules and I am not sure if this would be against the rules. Can I say on my site something along the lines of, "Please support our sponsors." My site provides a free service to the users and I am trying to generate enough adsense revenue to pay for the hosting costs. Once again, I am a newbie and can't decide if this would be a violation of the terms of use. Any guidance would be greatly appreciated.