What is the PR review process?

[gspencergoog]

I've read the contributor guide, and have successfully created a PR, but the guide just says "Once you've gotten an LGTM from a project maintainer...".

What's the process to locate and get a reviewer assigned to a PR? Should I go and look at who edited similar files and tag them on the PR? Also, it looks like two maintainers are needed in order merge (because of the Google rules): will the first one find and hand off to the second?

My PR will unblock progress on my project and so I'm naturally motivated to get it in.