You are asked to fill out an online application. Then you are given two tests for screening purposes. If your qualifications match their needs they will notify you. Understand that all agents working with this company are "independent contractors, " so you are not an actual employee of the company.
Translation: You need to set yourself up as your own "freelance" business. They will not offer you benefits, a retirement plan, refund of expenses, etc. They also can not promise you consistent work.
That's the thing about being and "independent contractor" it's up to you to schedule your work to provide yourself with consistent work and a consistent paycheck. Please be aware of this any time that you decide to take on a freelance or independent contractor position.
I advise you to carefully read their FAQ, especially the section entitled: "What equipment do I need to work as an Agent?"
Working Solutions has a lot of good information. Read everything, before applying.