The norm in Blog Advertisng now is the 125 x 125 pixel ad blocks. Almost every WordPress Blog is using format in their sidebars as it is unobtrusive and can accommodate as many Ads you wish.
Due the popularity of this format, many WordPress Theme designers have included this function into their them design. However, if your theme does not provide you with this facility and you love your theme too much to replace it with one that does, a plugin will do the job for you perfectly.
Please note that if you intend to place in rows of 2 horizontally, your sidebar must at least be 280 pixels wide. Otherwise, you will have to place it in a single column row like what you see at my sidebar demo. Still it doesn’t look too bad. In fact it is quite refreshing to see the Ads place like that. What you see in my sidebar are not Ads but just demos, but if you have itchy fingers and cannot resist clicking on pretty girls, please be my guest.
The plugin that I am using for the ads comes free from Unique Blog Designs. A widget will let you place your Ads easily to anywhere in your sidebar. It is simple and easy to use and the Ads rotate on each refresh. This way, your Advertisers can be fairly treated as the Ads on the top position always gets the most clicks.
To get the plugin, go to. You will have to sign up for their newsletter, but don’t worry, you won’t get spammed by these guys as they are not really Internet Marketers selling all those make money stuffs.
When you sign up, you will not only get the plugin, you will also get a free copy of their award winning UBD Money Maker WordPress Theme and an Ebook. The eBook is nothing much to shout about, but the Theme and The plugin is more than worth your trouble. At least you can now place 125 x 125 Ads perfectly in your WordPress Sidebar with ease.
Update 1st. March
I find the WP125 plugin much better in terms of Ad management than the one mentioned. Also widened my sidebar to see how it looks with 2 Ad blocks side by side.