What most naturally follows?

How to choose a credit monitoring service
Find a credit monitoring review site.
Not all sites are equal and some are actually run by the companies selling the services. Consumerreports.org is a non-profit site aimed at consumer protection, so they might be a good choice.
Next advisor, though not a non-profit, also aims to be independent in their reviews, and they are accredited by the better business bureau with an a + ranking. These are the places to go first, but you can also do an individual search on any particular company to see what comes up in a web search.