One of the most important elements in business, is trust. Because of this, a disclosure page is not only good practice from a transparency perspective, it makes good commercial sense too.
With 2 exceptions, see below, every link and recommendation I give here is done without any form of remuneration. Those I do receive remuneration for are services I use and believe in. When I link to an affiliate in a post, I always let the reader know.
Headway Themes: I am an affiliate of Headway Themes. This means I get paid an affiliate fee, when someone clicks on one of my Headway links and buys the theme. I was openly advocating Headway long before I became a paid affiliate.
WebFusion Hosting: WebFusion sponsor (pay for) the hosting of my sites. I am not an affiliate of their services, so I do not receive any form of payment when you click their banner in my sidebar. I was a very satisfied customer of WebFusion before they sponsored the blog and was already recommending them to everyone.