Knowing what type of information you need will help you figure out what type of resources you need BEFORE starting your research. This is all part of something called information literacy. Recognizing your information needs before you start searching will save you both time and frustration.
Here's the main types of information:
It is also important to understand how information flows in the information cycle. This is how long it takes information to appear in different resources (web, articles, books, etc). Knowing where you are in the information cycle will help you pick the right type of resource the first time.