I'd have a little explore round the SEOmoz "learn seo" section - really invaluable information.
Considerations for Targeting Specific Devices and Platforms using PPC
9/28/2011 In the last couple of years, the mobile web has taken off considerably. This has allowed advertisers to target content at mobile devices, users and reap the rewards. Structure your accounts properly. Firstly, account and campaign architecture based around devices is key. Create your campaigns based on the individual devices you are targeting. This will all...