I strongly believe in using entry pages or "splash" pages. I suggest that there be no images on them, and if any are used, only images that could be found in the Kmart circulars [swimsuit stuff]. There should be an entry link that follows a warning that entrance is to an adult site and that the surfer affirms he is of legal age. You can and should have an exit link, and going to a place like Patti's muscle boys site is a good idea because it may generate a sale or two where otherwise there is no chance of income. You can also put up links to places like netnanny or cybersitter if you have complied with their requirements.
A warning page is not age verification [there is no such thing on the Internet as Age Verification, because a surfer can always use someone else's info and you cannot inspect their ID like a bouncer at a bar] but it does show a good faith effort.