First time juicer-- grocery list?

I want to do a week long juice fast right after finals (so starting this thursday :D). I have a juicer that my mom got at a tag sale. It's really old and not high end or anything, but I think it should do the job.

I tried clicking on the "some basics for trying out" under the FAQ but it won't load for me =\

So, what should I buy this week for groceries, if I intend for this one trip to get me through a week of juicing?