They are very good with their training program, however, it does take some time to complete it before you can start with them (up to 1.5 months).
The sliding pay scale for entry-level proofreaders ("proofers") ranges at the low point of $15 up to $25, depending upon assessments of your work after submission. There isn't a lot of advancement here, but sometimes they need cross-trained proofers to do editing jobs, which then bumps you up to a flat hourly rate for editing work, however, this is by invitation only and further training. The downside is the seasonality of work available, so there are periods of up to 1 month between the 4 peaks with no work, so it isn't career work. But as supplemental income, can be very lucrative. Required 20 hours per week during peak periods or they may delist you.