The U.S. Citizenship and Immigration Services announced on March 7th that the new and improved I-9 Form is available for employer use. Technically, you can use the old form until May 7th. But since it's out, why not use the new form? The format is different and appears to be easier to understand and use. Hopefully, there will be fewer errors by employers, particularly where to sign.
A link to the new form is here: www.uscis.gov/files/form/i-9.pdf
Keep I-9s together, in a binder. It will make life easier if you are subject to an audit. The forms must be kept for three years or for one year after the date of termination, whichever is longer. Have a document retention policy that calls for destruction of old forms after the mandatory retention period. Then follow through with the document destruction.