The Los Angeles Times stylebook adopted Latino over Hispanic in 1995, or even earlier. A recent update seeks to clarify the usage and the reason behind it.
Latino is the umbrella term for people in the United States of Latin American descent. It refers to Mexicans, Puerto Ricans, Cubans and others from the Spanish-speaking lands or cultures of Latin America. A Latino woman is a Latina. It is preferable to say that an individual is Mexican American, of Salvadoran descent and so forth, instead of using the umbrella term.
Keep in mind that Latino is an ethnic group, not a race category. Latinos may be of any race: white, black, Native American, Asian, mestizo, etc. Some speak Spanish; some don't. Some are U.S. born; others are immigrants.
Note: Hispanic is acceptable in quotes or in proper names. The U.S. Census Bureau uses terms such as "Hispanic or Latino" and "non-Hispanic or Latino" in its survey questions on ethnicity and race. Stories and graphics based on census information are allowed to use that language when it is essential to explain methodology, but we should otherwise use Latino to describe the people in question.
Assistant Managing Editor Henry Fuhrmann summarized the rule in a note to copy editors: "So, to be clear: Latino should be used in nearly all contexts; the exceptions, as described in the revised entry, must truly be exceptional."