Online Resources:
Desmos (Desmos is an online graphing utility. It's super useful!)
Wolfram Alpha (Wolfram Alpha can solve many of life's problems, including your math ones!)
Khan Academy (Khan Academy is a website that offers free educational videos for a wide variety of different subjects, including math!)
Paul's Online Math Notes (Paul is a professor at Lamar University. He has very detailed notes on calculus courses.)
Calculus Calculator (This website has a ton of different calculators to help find things like various derivatives and integrals.)
Here are some great YouTube channels that I recommend for extra help:
NancyPi (Nancy is a graduate of MIT and has some really accessible videos on YouTube that help for classes ranging from algebra to calculus.)
PatrickJMT (PatrickJMT uploads free educational videos to YouTube.)
Organic Chemistry Tutor (Has videos for several different subjects in STEM.)
Black Pen Red Pen (Several math videos where he uses a black and red pen to help emphasize different math topics.)
3Blue1Brown (Really great, high production value videos to help better understand the conceptual knowledge of various math topics.)
Other Resources: