Autodock is the best software for protein-ligand docking. It is available in GUI as well. Go though the tutorial: autodock.scripps.edu/faqs-help/tutorial/using...for-virtual-screening/VSTutorial2.pdf
Virtual screening can be done by several approaches such similarity searching, molecular docking or QSAR. I suppose you refer to molecular docking, as stated above you can follow the general tutorial of vina. But if you are also interested on the background of this techique you can check the following papers: