You must be 16 years or older by March 31, 2014, have a valid Comic-Con Member ID (you can get one here when available), have your own accommodations, and be willing to work 2-3 hours per day to apply.
When not on assignment, volunteers get all the perks of paying attendees. This might also be the best chance to volunteer at a con this size since San Diego Comic-Con International has already closed their volunteer registration for this year.
To register as a volunteer, log in to your Comic-Con Member ID account and click the “Volunteering” tab. You will receive further instructions once you've applied.
For more information about WonderCon, visit http://www.comic-con.org/wca.