What is the best method of placing display advertisements on my WP website?

Hi Adrian, I usually just paste the ad code furnished to me from the advertiser into the page, post, or sidebar widget — in Text mode, not Visual mode. But if that doesn't work for you, there are several plugins that will make this much easier for you. Our friends at Elegant Themes recently compiled this excellent list of the top advertising plugins for WordPress. Hopefully one of those receommendations will fit the bill!