Below are some helpful websites and resources that I think could be helpful for students in any mathematics class. Provided with each is a description as to why I think they may be helpful or how they can be used.
1. YouTube
While some may think this is an odd choice, I find it very helpful to watch videos on things that I am learning. Having a visual while someone else is directing you through a process can be extremely helpful. You can search practically any mathematics topic in YouTube and you will find instructional videos on the steps/techniques for the topic.
Disclaimer: Not all videos are of educational quality. Be aware of what you are watching.
2. Khan Academy
Khan Academy is a highly accredited website that provides students with tutorials, extra practice, and an organized way to complete work.
3. Kuta Software
Kuta Software provides multiple worksheets with solutions for students to complete extra practice. I use this source as an extra practice within our classroom as well as for homework. It is a good resource to use for review before taking a quiz or test.