All of the sources listed in this guide can be used to various degrees no matter the industry. Here are a few of the reasons some industries are going to be difficult to research:
Conversely, it will be easier to find information on "big" industries--those dominated by public companies and/or highly regulated.
There are a few general things to keep in mind which other sections of this guide will focus on a bit more.
Some of the best sources for information on a specific industry are done by publishers focused on an industry or industries. For example, Informa (Datamonitor) IHS, Plunkett, or S&P's Market Intelligence (SNL/Kagan) and Platts all either focus on industries generally or have historically looked at a particular one. It should be noted, that while industry reports may be available directly from such publishers or from aggregators like Marketresearch.com, External these reports can be quite expensive and since they are often not part of any library's collection it is not likely that they will be something that can be borrowed.
One way to get at some information is to look at filings companies make with Securities & Exchange Commission and other regulators. If you do that for several companies a bigger picture will emerge. More discussion on this is addressed by clicking on Research the Companies in the left navigation.
In those cases where it may be hard to find industry information, getting creative will be important. Information will be harder to obtain and most likely come in small pieces that are then put together to form a bigger picture. Briefly, here are a few suggestions to search for hard to find industries (or if you don't have access to databases), but other parts of this guide will provide more detail and links to sources: