Here's a sample ad.  Most rotate between 3-5 slides.  

Logo

Add your specialty - a promo - your phone # - or a good image respresenting your business

Action slide - Add your website address - or Click here for more info

Here it is animated:

Other ideas - Highlight your services, use photos.  Keep it simple, the purpose of the ad is for people to click on the ad if they want more info.

You will get over 2,000 impressions a day with this ad!