There are many great resources freely available on the web. Many instructors permit you to use credible websites from the web, but some do not. Check with your instructor, syllabus, or rubric for clarification. Take the time to evaluate each source found on the open web, or choose from the trusted sites listed below. If you need help determining a web's credibility, follow the steps in the video below. Library staff can also help you with this.
This video created by the Oregon School Library Information System provides guidance to determine the credibility of a website.
Watch this video by the Science Elf for an answer to the (Digital) Age-old question. For an alternative to Wikipedia, check out Credo Reference.