1. An image forming apparatus comprising: a storage device to store a plurality of documents; a user input device to select a complex document having at least two documents in a predetermined order among the plurality of documents stored in the storage device and to select a number of copies to be printed for each of the at least two selected documents; a print engine to print the selected number of copies for each of the at least two selected documents; and a controller to control the print engine to print the at least two documents according to the predetermined order and the selected number of copies.