Does not boot (endless spinning)
Newly purchased Macs come with 90 days of complimentary AppleCare phone and web support (as well as walk in service at all Apple retail stores). 

You will want to follow the internet recovery steps to erase the drive and reinstall the operating system once you have ascertained that no data (pictures, documents, etc...) exist only on that Mac.

Here is the script you will be following in a nut shell:


power off the mac
boot with Command and R held down
select Disk Utility to repair or erase and re-format the drive (GUID partition scheme and Mac OS Extended (journaled) format for the volume.
download and install Lion from the internet recovery
attempt again to set up the mac


Do consider that a hardware failure could cause things to not work as intended - a call to Apple is the fastest way to get that sorted for someone that isn't used to isolating issues on hardware.