Hosting/ streaming site mentioned in tool # 3 are all good, but the one I found most useful for my content is mathtv.com because it is organized by drop down by math topics, there are more than one person who teaches the same problem, and most videos include a Spanish version as an option for students who do not speak English. I do have an account with dropbox and it is very convenience to store files and access them anywhere from a computer, smart phone, or tablet. It is very useful when you create a share folder for your students to access files/ assignments from home.
Solve Quadratic by Factoring
Solve Multi Step Equation with Variables on both Sides