You Know Me Al: A Busher's Letters (Library of Essential Reading Series)
Several publishers have it in print, there are lots of used copies floating about for sale, libraries always appreciate your patronage, or you can read it online. Take your pick.
From Barnes & Noble Books:
Ring Lardner's first published fiction created a sensation, catapulting a regional sports journalist into the national literary spotlight. Presented as semi-literate letters written to a friend by a baseball player embarking on a professional career, Lardner's short stories first appeared in the Saturday Evening Post in 1914. Readers couldn't get enough of "busher" Jack Keefe, the unpolished, exasperating, charismatic narrator. Since being published in book form in 1916, You Know Me Al has retained its place on the list of essential readings in baseball literature. In a 2002 ranking of the one hundred greatest sports books ever, the editors of Sports Illustrated placed Lardner's masterpiece at number five.