Enroll in a Latin class at a local university or community college. Because Latin is a "dead" language, the only place you are likely to find others who speak it and engage in conversations will be in an academic setting.
Consult lesson plans and vocabulary sheets that are available on the Web. While learning a language on paper without the assistance of an instructor is very difficult, this may be a good method for a person who wants to learn the language as a hobby.
Consider purchasing language-teaching software such as Rosetta Stone. Different types of software will feature different methods and prices, so shop around for the one that suits you best.
Find a local tutor or instructor to engage in one-on-one lessons. Working on an individual basis is one of the most effective ways to learn a new language, and the personalized attention will ensure that you learn quickly and correctly.
Study and practice. When learning a new language, there is no substitute for doing the homework, learning the rules, and speaking it as much as possible. The more Latin you speak and look at, the more quickly you will learn.