If you want to practice contents on your own, check this webpage called ISLCollective. You can register as a language learner and get access to free video lessons and worksheets (with answerkeys) if you don't register you could access to some of the worksheets as well.
ESLTower.com is a free ESL, EFL site that offers top quality printable and interactive English grammar, vocabulary & pronunciation exercises for teachers and students.
Education.com offers digital resources, tools, and learning materials developed by educational experts. All the materials are very useful and can be used to support the education standards. Even though you are registered, there's a limited number of free downloads per month.