Back in March, timeline appeared for your business pages and along with it came some new rules.  So keep the following in mind when making up your Timeline pic.

Cover images must be at least 399 pixels wide and may not contain:

• Price or purchase information, such as “40% off” or “Download it at our website”
• Contact information, such as web address, email, mailing address or other information intended for your Page’s About section
• References to user interface elements, such as Like or Share, or any other Facebook site features Calls to action, such as “Get it now” or “Tell your friends”

All cover images are public, which means anyone visiting your Page will be able to see the image you choose. Covers must not be false, deceptive or misleading, and must not infringe on third parties’ intellectual property. You may not encourage or incentivize people to upload your cover image to their personal timelines.

Now if you haven't got a timeline pic, those good guys at trickedouttimeline.com have made an application that does it all for you.  Go check them out and pretty up your page.  Takes 5 minutes, tops.