Photoshop can automatically create a contact sheet featuring some of your favorite images. Using the command FILE > AUTOMATE > CONTACT SHEET II, you will get a dialog box asking you how you want your contact sheet constructed.
Don’t import a color image and select the IMAGE > MODE > GRAYSCALE command to convert it into black and white. If you do that, you will literally throw away two thirds of your valuable data that you can’t get back later! You will also end up with a flat, drab-looking image that will make a turkey puke.