Is it permissible to receive payment from a bookstore owner for printing work, while enlisting the help of another person for a portion of the work in exchange for a wage agreed upon between me and him?

Your work in printing papers on the computer is considered a joint lease (ijarah mushtaraka), and it is permissible for you to hire someone else for this work for less than your wage, provided that the conditions of the lessee regarding the quality of work are met.