The new season premieres on Wed. July 23rd at 9/8c with Cynthia Nixon. I usually watch every episode, even if it features a celeb I don't like. I may change that policy this year with Kelsey Grammer. He makes my skin crawl.
The shows official FB has a video tease for the whole season. This page has a preview for episode one:
Who Do You Think You Are?: New Season: TLC