Well eagle definitely is an easy way of getting gerber files out to ITead, as they have a .cam file for eagle available for download on their site.. Just need to load the .cam file and eagle will output the required gerbers.
Eagle might not be the most intuitive program to learn, so if you have no experience with it yet, it may be worth while to look into other packages, for example many like Diptrace. But I've been using eagle for years now, and I like it, it has a traditional "command console" which IMHO makes it quite powerful.
Been using ITead half a dozen times of too, no problems ever with them. And you really can't beat the price =)