Okay, there's a lot of information on Accreditation Now and in the CARF® manuals. Where do I start?

Print out the Appendix A: Required Written Documentation from the back of the CARF® Standards Manual.
Starting from section 1, go down each item--if you have it in your policy and procedures manual, then check it off; if you don't, then download from Accreditation Now. Update with your information.
After identifying that you have all the documents, then go to the front of the book and ensure you have each item the manual requires (e.g., "is the policy reviewed annually"). If not, then make a plan on how you will meet the standards (e.g., "we will review at the next management meeting and again annually"). If you do meet the standard, then you are good-to-go with that line item.