A high fiber diet should include food such as beans, whole grain cereal, and power bars. I recommend eating a lot of lentils, because they are the best tasting of all beans. Not red lentils because they are gross. The typical green ones. Even the French ones if you would like.
You should include steel cut oats and whole grains in your diet. The breads you choose should include at least 3 grams of fiber per slice. Also, plenty of fresh vegetables and greens. The closer they are to their natural state, the higher their fiber content.