Once you've found some sources you think are appropriate for your research project, it's time to evaluate them. (This goes for print sources just as much as internet sources.)
Remember: Even if your sources meet all the criteria above, you still have to make sure they actually help you with your project! A perfectly reliable source of information that doesn't help you answer your research question is not useful.
As you conduct your research, you may realize that the question you're asking is misguided, not very interesting, or impossible to answer. What's a student to do??
Change your research question!
Revising your research question based on knowledge gained from research is all part of the process. You may need to inform your professor of this development, but don't be afraid to change course.