flea markets in Tokyo

I will be studying in Japan, and I am interested in going to a Flea Market in Tokyo. I am wondering which flea market is the best to go to? By the way what do they usually sell? I am interested in buying Japanese books, and CD's? Do you know if they offer these items?

thanks

If you're looking for books and CDs, a chain of stores called "Book Off," which sells second-hand books, might be better than a flea market. For new stuff, the Meiji Park or Yoyogi Park flea markets are probably best. For older things, the Togo Shrine (1st, 4th, and 5th Sundays) and Yasakuni Shrine (usually 3rd Sunday) are best. The Tokyo International Forum flea market seems more upscale and artsy to me, but has interesting things. The Ueno flea market, held next to the pond in Ueno Park, is next scheduled for July 17th to August 4th, but is smaller than the others I've mentioned.

Here is a website which gives a month-by-month guide to the major Tokyo and Yokohama flea markets/antique markets:

http://events.paperlantern.net/month.php

(if you go to the "category" field and change it from "all" to "flea market" you'll get a clearer list).

And this page has a description of the main regular markets and their locations:

http://www.paperlantern.net/fleamarket/

I suppose I should have updated this long ago. For the past year, the Yasakuni Shrine flea market has been every Sunday, and for some time now, the Togo Shrine market has been only the 1st Sunday of every month. My apologies to anyone who was misled by my failure to update when these changes were made.