Research is one of the terms that people find intimidating. It doesn’t have to be! For SCA purposes, research is simply finding something written about your topic, and reading it. And while you shouldn’t rely on it for the final say on any matter, Wikipedia is a good place to start. It gives clear overviews (usually, anyway) and links to further information.
You can also find plenty of material that’s been written by other people in the SCA. Just dropping the thing you’re looking for information about into Google, with “SCA” on the end, can help you with most things. So searches for “medieval cooking SCA” or “renaissance leatherwork SCA” can get you directly to other people’s work. And then there’s the treasure trove of previous work that is Stefan’s Florilegium Archive, which contains decades of material from mailing lists, newsgroups, and other community sources.
If you’re not getting anywhere there, it’s time to break out Google Scholar. This resource indexes all manner of academic books and papers, and you can usually find stuff here within a few minutes. You’ll have to dig through some academic language to get at it. Sometimes you’ll get links to whole books that are on Google Books, and sometimes to academic papers. If you can’t get to the full text of the papers, see if you can get a friend who has access to academic libraries to get them for you. And of course, your local public library may be able to help with this, and with access to books, either on their own shelves or via inter-library loan.
In addition, don’t be afraid to ask around in your local SCA group. Many SCAdians have extensive libraries on their particular interests, and no matter how obscure your topic is, you’ll be able to find someone who has a book about it.
Once you’ve located your reading material, read and take notes. Notebooks work well for this, but loose-leaf A4 binders, index cards, word processor files, text files, and cloud-based services like Google Docs can all help too, depending on what you’re used to. After a little while, you’ll start to see connections between different bits of information, and references to particular books. If you see references to a book in three or four different works, you know you’re onto something important, and if you can get that book, you’ll be reading one of the more important ones on your specific topic.
Research can be slow, particularly when you’re looking for a hard to find book, but ask around, and someone will be able to help you find it. It may look like something you do on your own, but in reality, research always goes best when you can involve someone else.