Do you use standardized training manuel? or did you develop one on your own? For small caterers, most use temp help either through a staffing service or through word of mouth. I know of bigger houses doing inservice on a regular/quarterly basis, to present new menu items and bring newbies up to speed. One of the long time caterers has waitstaff training on DVD's, has a test they need to pass prior to being sent on a job. One of the biggest headbanging truths I learned years ago was that it does not matter how good the food is, if the waitstaff are obnoxious or not in service mode, they sink the whole show.