How to find out what factories a particular company uses:

1. Use Global Amen's Company Profiles
    I've been doing a lot of research myself, particularly in the area of the garment industry. You might want to check here first to see if I've already made a list of some of the countries and factories in which the company has produced. Keep in mind that the lists may not be complete, and may not be current . . . but hopefully they'll give you a start!

2. Find the Countries in Which the Products are Produced
    Even if what you're going for is the name of the factories in which a certain company produces, your searching will be much easier if you know the countries in which they manufacture. Many products will include tags or permanent labels with the country in which they are produced on them. You could also try e-mailing the company and asking them. . . but don't expect much, I've e-mailed over a 100 and not one of them has given me a list of countries yet. Your best bet is looking on the product itself.

3. Use The Global Amen Technique
    I have developed my own method for finding factories that a particular company uses. It seems to be the most effective so far. It's a little complicated so bear with me as I try to go through it:
     1. Get the Google Toolbar. If you don't already have
         it, you will need to obtain the Google Toolbar. Go
         to http://toolbar.google.com/   and go through
         the download and installation process. The toolbar
         will be installed in your browser window, but can
         be turned on and off.
     2. Go to an appropriate site listed here:
         Global Amen's Factory Links
     3. Put the company's name into the Toolbar's search
         field, and click the "Search Site" button. This will
         allow you to find all the pages within that site
         which contain your search terms. Keep in mind
         that the "Search Site" feature will not work with All
         websites, but does work with most.

4. Look on other Anti-Sweatshop Sites
    Anti-sweatshop organizations usually mention a few sweatahops and the companies that buy from them on their sites. You can do a search for anti-sweat organizations, but you might want to try Global Amen's Research Links first.

5. Look through News Articles
    There are quite a few newspapers whose contents are available online. There are often archived articles from past years too! Alternative news sources are generally more helpful, but you may find some info in mainstream sources as well. Try doing a search with the company's name, the word "factory" or "sweatshop" and one of the countries you found in step 2.
Alternative News/Media Sources
Mainstream News/Media Sources

6. Use a Search Engine
    Type in the company's name and the word "sweatshop" or "factory" or "manufacturer" and you might be able to find some information. Here are some search engines I like:
Google
C4
AllTheWeb
Ask Jeeves