Compost materials are often categorized as either 'greens' which provide Nitrogen or 'browns' which provide Carbon. They are also known as wet and dry materials, respectively. Food scraps, green (as opposed to woody) plants, lawn clippings, and tea bags are all examples of 'greens'; while leaves, straw, and twigs are examples of 'browns'.
Manure from herbivorous animals, such as rabbits and chickens makes a great, nitrogenous addition to your pile, especially in winter when it can be used to jump start the process and heat up the pile during the cold months. However, be sure to keep the standard ratios of one to two (1:2), green:brown for best results and the quickest decomposition.