Although grades 6, 7, and 8 in New Jersey don't "officially" make the switch to the new Math CCSS until next September, my district decided to take the plunge early. (In fact, I helped rewrite the curriculum for all three grade levels.)
Whether or not your district is implementing the changes this year or next, it's always good to start gathering resources now. This is a great website. It has sample math assessment questions for just about every standard for every grade level.
This website also has sample questions for both Math and ELA for grades 3-8. And, the NCTM has created a suite of computer tools based on the common core standards. Download it here.
In order to keep track and to make sure that I cover all of the new standards, I created a checklist for grade 7 and grade 8. They have been really helpful in figuring out what I need to supplement and what I no longer need to cover. They are the most popular items in my TeachersPayTeachers store as well. I'm glad they are assisting other teachers with the transition.
Here's a link to my 7th Grade CCSS Checklist.
And, here's a link to my 8th Grade CCSS Checklist.
I hope they can help you as well!