As you consider OER, remember first your pedagogical objectives. If an entire resource doesn't work for you, could a portion of it be helpful? Because of the open license, you can consider combining large or small portions of multiple OER, in addition to considering fair use for small portions of other works.
Below are some checklists of items to consider when determining if an open resource will work for your course:
How do I adopt an open textbook and include it in the SPU Bookstore listing for my course?