The best site I have found for CRRN continuing ed is
www.CEUs4CRRN.com. There are over 100 courses available and all are approved for CRRN. They offer a very wide range of topics, many very interesting and relevant to rehab nursing. All the courses are online (though the courses AND the tests can be printed off and taken offline -- which is what I did).
I read the course content at home and filled in the test answers as I read the material. I just returned to the website to enter the test answers. The test is graded instantly and then I printed off my certificate -- very easy. They even tell you which questions you answered wrong so you can go back and fix the wrong answers!