I'm so glad you are doing your research and you are definitely asking the right questions. I am actually an enrollment counselor for Grand Canyon University and would be happy to answer any questions you have and point you to some resources to research.
Accreditation is the MOST important thing when you are choosing a college: visit http://www.elearners.com/college/gcu/ for specific information on this.
GCU is a traditional private Christian college with dorms, sports...etc. and has been around since 1949. A LOT of their programs are now 100% available online, including the RN to BSN. Some of the highlights of GCU's program that differs from others you will find is that GCU does a "block transfer" of your credits so you won't have pre-requisits like Algebra to do. It's 15 classes, 100% online, no clinical rotations, and no manditory outside group work. It's designed and taught by RN's. I wish you the best in the search for the right BSN program! ~Kim