Not really sure what Common Core is all about? Hear are some tools to help you learn more about it.
Home School Legal Defense Association (HSLDA) has a nice 7 minute recording, Navigating the Common Core Maze, to introduce you to common core and how it affects homeschooling. They also produced a 39 minute documentary, Building the Machine, which gives a more in-depth introduction into how common core came to be. They also have a website devoted to information regarding common core, HSLDA Common Core Issues.
Ohioans Against Common Core also has information on their website about common core and current state initiatives.
Freedom Project Education also has some valuable videos testifying against common core on their website
You can also view the standards themselves here: