Do you mean the Food Optimising book that you can buy from bookshops with mostly recipes? If so then no it won't give you all the information about the SW plan because then people would have no incentive to join as members.
Healthy extras are there to make sure that you have recommended amounts of calcium, fibre and protein in your diet. If you take a look at the thread for newbies in the section about explains more about it. The number you get depends on the plan you are following but basically 'A' choices are milk and/or cheese and 'B' choices are bread, cereals, cereal bars, oil, dried/stewed/canned fruit, some canned soups, wholemeal pasta (on red), meat and fish (on green), nuts/seeds/cheese (on green). There isn't a list but we can give you advice on what you can have and how much you are allowed of each.
Hope that helps