There are quite a few things that you will need to do to setup an onboarding setup.
First thing you need to do is setup a standard 802.1x service. Here is a tech note to get you started.
http://support.arubanetworks.com/DOCUMENTATION/tabid/77/DMXModule/512/Command/Core_Download/Default.aspx?EntryId=10345
After that I would recommend working with your local partner.
You are going to need to setup
1. Controller (with multiple Roles)
2. Onboarding SSID
3. Secure SSID
4. Certificate (must have a public signed cert to onboard IOS)
5. Onboarding Pre auth service
6. Root CA
7. Onboard Networks Settings
8. Onboard provisioning profile
9. Im sure I missed a couple off the top of my head :)
Here are a couple work flows