Hi Mona, Welcome to the forum. I've worked with International Service Check, and they are great to work with. They respond quickly, almost immediately, to emails and pay on time. Their pay is commensurate for the shop and report requirements. They have a nice variety of clients. They have a website, but don't post their jobs there. They offer jobs through emails, and the emails don't come very often, so I sign up for shops as soon as I can. They are a European company (Swiss), so they can't be expected to know how far apart US states are, so your "nearby" shops might be one or two states over, but that happens with US companies, too.
At the bottom of each forum page is a link to legitimate companies. Start signing up with the companies on that list and read all the posts in New Shopper section of the forum, and you'll be on your way!