Creating WCF Webservice

In my application I need to create a WCF webservice.
We get info from a third party iphone App .
We are a marketing company. Basically we get info from
different source.
One of the source is from a third party iPhone App.
Suppose when a user clicks on a Handbag and sends the photo as
an attachment, when the user submits his picture we will receive
his name,phone number and the picture of the handbag(as attachment).
Our WCF Webservice needs to receive that info and find out the zip code
based on the address(we have look up tables for Zip code) and send the
data to the database.
So for this I need to create a WCF Webservice(WCF Service Application).
I am new to WCF.
I really appreciate if you guys can provide me some code to how to do this.
We are using VS2010,C#,ASP.Net and we are going to launch it on IIS.

Thanks inadvance for your help.