THE AFRICAN AMERICANS edited by Charles M. Collins and David Cohen, text by Cheryl Everette, Susan Wels and Evelyn C. White. (Viking Studio Books: $45.; 240 pp.) "The African Americans" takes its rightful place among the growing library of photo-documentary books recording the black community. Though it covers much of the same ground as other books, the vividness of the color and black-and-white pictures, layout and descriptive captions place it in the must-have category. Contemporary and historical pictures, taken by a cadre of skillful photographers, highlight the famous and ordinary folk who sustain the culture. Kevin Horman's photograph of Mike Davis, a high school senior, studying at the kitchen table after his shift at the local McDonald's eloquently suggests social pressures, as do a striking profile of the Rev. Jessie Jackson, a priceless picture of Harriet Tubman and the above portrait of William T. Pratt, Deputy Imperial Potentate of the Free Masons, African-Americans' oldest continual fraternal organization.