For healthy skin, get plenty of foods that contain essential fatty acids, especially Omega 3s which are found in oily fish (mackerel, tuna, sardines, herring, salmon), plant oils (olive, rapeseed, grapeseed and nut oil) and nuts and seeds (walnuts, hazelnuts, pine nuts etc). Make sure you get enough of the good stuff by dressing your salads with different oils each time and eat fish at least 2-3 times a week.
To keep your hair healthy, take B Vitamins from natural sources: whole grains, eggs and pulses. And for your general beauty, eat cooked or raw fruit and veg at every mealtime. They're packed with excellent nutrients, water and fibre.