I find I use these 2 rulers the very most. 6" x 23", And a 6" or 8" bias sq for squaring up. Yes, no matter how careful I cut or sew, I always have a problem with my blocks bieng the right size. I hope this won't be a problem for you.
A big welcome to you from a new resident of Paducah, KY. I hope you spend many happy quilty hours. And find lots of companship and help here on the board. Look forward to seeing your finished quilt.