I am on a J2 visa, do I need an EAD for an unpaid job/unemployment.

Yes, you do need an EAD for unpaid job. USCIS (formerly INS) does not allow any type of work on a J2 without an EAD. I would imagine, however, you might again get away with something you do for a month or two (for example an unpaid observership) - but it is again taking a risk. You can go to the USCIS website for information regarding application for EAD:

http://uscis.gov/graphics/formsfee/forms/index.htm

You need to fill out the form I-765. The whole process takes about 3-4 months - the application can be submitted online with the payment and the supporting documents can be mailed later on. I believe that in case it has been more than 3 months since your date of application and you still have not received an EAD (which is usually the case) - you can go to your local USCIS office and get a temporary EAD.

Navneet