How Do I Make A Poster On A Food Chain?

My daughter has a project which is due tomorrow and when we asked her teacher where to find the info. She said online and sounded so simple, but not so simple when you don't go online to research anything and everything we type in seems to be like a book on our subject but we need to buy and we was told that it was free of use if we go online. So could someone please show me the door to the ez free use info on food chain. Thank you