All of these companies have been researched and are known to hire people who are looking to work at home. Some of these companies may require that you pay for your own equipment such as a foot pedal, headset and even a background check or to become incorporated. This is perfectly normal.
Some companies hire on a continous basis, so you will want to apply to those first and for the others, bookmark them and check back frequently to see if positions become available.
Here you will find quite an extensive list for the following job categories.