Types of Resources
When doing a report, a project, a thesis, or research, there are a number of places you can go to get reliable information that can be taken series in a discussion of your topic of research. These types of resources are essential to any good research. If you are trying to draw a specific conclusion, the facts you choose to support that conclusion have to be rock solid, or the entire conclusion collapses in on itself. This site will tell you some basic tips for how best to use these types of resources so that you can build a solid argument.
There are some sources that just aren't credible. Say, for example, you heard that when you flush the toilet, the air bubbles coming out at the end send a cloud of poo microbes into the air, thus infecting everything in a six-foot radius with poo-ecules, including your toothbrush. While this may be an excellent fact to put in your article on poo microbes, you have to look at where it came from. Did you hear it from the friend of a friend? Or your microbiology professor? You must be able to source all of your facts, so if you have any direct resources, you must make sure they are an authority on the subject you're discussing, or at LEAST have some direct, relevant experience. It is also important to note if they have any stake in what it is you're trying to prove. Is there any reason for them to lie or exaggerate to you? Has this source been reliable in the past? Will they be getting a large subsidiary chunk of change from the government for poo-ecule research when your paper is published and proven?
If you aren't dealing with a direct source, credibility is still important. Wikipedia, for example, is not considered a credible resource, simply because it's possible for anyone to edit that article in a relatively anonymous manner. How can you know if the information is good if you don't know who it is coming from? Aggregate commons sites like Wikipedia are useful, however, in that they often DO site their sources. You can go to these sites and then follow the links to the various sources they list, and then use those sources for your research. Typically, however, the internet is a dangerous place to do research, because it is difficult to enforce libel laws and various other sorts of legal fact-checks on anonymous authors. A published book that claims to be non-fiction most likely had to go through at least some semblance of fact-checking, whereas your internet source did not necessarily. This isn't to say that books are infallible, but as a rule of thumb they're safer than the internet. If you're going to do research on the internet, make sure you stick to credible resources and not Jimbo's blog.
Types of Resources
There are a number of places you can go for research that are acceptable in an academic or journalistic sense. These sources are easily divisible into Primary and Secondary resources. None of them are infallible, but primary are generally higher regarded than secondary types of resources.
Primary Resources are raw, firsthand material. They are firsthand accounts of events, or raw data collected from a specific experiment. These types of resources are considered to be the closest to the actual true event/experiment, so they are given higher standing. If you are writing about the D-Day invasions, you'd be best served to look into a Marines' account of that day, or to read Dwight Eisenhower's memoir. These would be primary sources, because you are taking their firsthand accounts. Note they still aren't totally reliable, because the source could, for whatever reason, be lying or mistaken in their accounts of the day. But it will be held in higher regard.
Secondary Resources is anything that offers an interpretation or conclusion on the primary resource. If you're doing research, you generally want to find secondary resources from experts who agree with you, or at least can support the specific point you're trying to make. It always helps to have academics and experts backing your point. Otherwise, people may get suspicious that your research is leaving something important out, or that it is not really held seriously in the scientific or intellectual community.
Both of these types of resources are necessary for any research. Now let's look into different places you can go for your resources.
Where to Find Information
The internet is probably the largest and most easily accessible resource at your disposal. The problem, of course, is that there isn't any regulation of what content gets put on the internet. Any idiot can post anything, so you can't take it at its own word. That doesn't mean you shouldn't use it, however. There is plenty of reliable material on the internet, the key is to follow up on whatever information you find there and fact check it. Is there a number on the site you can call for the information? Are there any other reports that seem to corroborate the one you've found online? Can you get in touch with the original writer? All of these are good ways to make sure.
Newspapers are usually safe resources to go to when you're looking for information, simply because newspapers stake their reputations on accuracy. It is the general rule in the newspaper industry to keep the story as close to the actual event as possible with as little commentary as you can. If a factual error is made, it is usually corrected quickly. Because of this, you can normally put a decent amount of stock in an archived article of the New York Times or Wall Street Journal.
As said before, books are one of the best places to go for resources for the same reason as newspapers. Books are put out by companies, and companies have reputations to uphold, so they are less likely to have inaccurate information in them than on the internet. This alone is not enough, however. You should still check the authors background and fact check anything you take from a book.
These are one of the most extremely reliable types of resources. Each article written in an encyclopedia or entry in a dictionary is written by experts, so there is usually no reason to think you aren't reading up-to-date (as of time of publishing), accurate information that can be trusted in any report.
As long as you document and prove your original research, this can be incredibly valuable in proving your point. If you are adding something new to the intellectual commons, people will be more open to the idea that you may have discovered a new thing that more or less proves your point. Original research is extremely valuable, but keep in mind, the accuracy of that information is attached to YOUR reputation.