2. Not washing your hands before handling food or after handling and preparing raw meat. From polluted water and contact with human or animal waste. So always wash your hands after using the toilet or playing with/stroking pets. And bear in mind that cats and dogs clean their genital/anal area by licking. Have pets de-wormed regularly. Eggs can be in the body of an animal or human host for years before they develop into worms.
3. For more information see the related link.