I usually just google the restaurant to see if they have the nutritional info and then use my points calculator.
As Kelly said, the restaurants change their menus and the WW books are not that up to date - its' even harder with the Canadian dining out guide.
If you eat out quite often then it is a good idea to pick what the best options are and make a list of the items with points for future reference so you don't have to look them up each time- your own personalized dining out guide