What are you looking for specifically?
Research is a huge sector, companies pay good money for info and statistics.
Whenever in doubt you can check out government websites, since they too, do
research every quarter or year on industries.
The best thing is that they archive most of their findings, so you can actually
take a look, compare, and predict trends in the market.
Here's an exmaple:
International Market Research - Fashion Accessories Trade Mission
government websites like those are filled with info on research of various industries, so if
your looking for general statistics and info on say the fashion industry, you can dig deep and find it.
If your just looking to see if your product sells,i.e.... an urban/street clothing line
then you could just ask around on forums blogs et.c, ask your potential customers(teens) skaters,
you get the picture, and get feedback from them. Thats considered research too.