Prior to capturing the image you need to enable the default "administrator" account and set the password to a known value so you can enter those credentials in the wizard when creating the project/target list to deploy. This account/password will be used to log into the system to finish up the deploy project as the system will reboot (a couple of times) especially if you also join a domain.
This was mentioned in one of the recent posts on "how to" OSD documents.
If you capture a standard WIM image (no sysprep) it does not require the additional steps.
Hope this helps,
Here are links to the how to posts Steve mentioned above:
and a full list of the OS Deployment article series is available in this blog post: OS Deployment information series - updated Mar. 10, 2014