Order a copy of safer food better business from the direct gov website. It is a workbook for any food business which guides you through all the necessary procedures.
As to what environmental health are looking for.... It depends a bit on what your business is. If you use high risk ingredients they will expect more of you. They are usually very helpful, and want you to be successful, and I would consider phoning hem up and talking through your business plan with them, and they will help you to set things up correctly from the start.
They wil want to see you using sfbb as a working document.