Decide how you wish to learn Greek and Latin. Ask yourself the following questions: Are you primarily an auditory learner, or do you respond better to visual cues? Are you disciplined and good at self-study, or do you work better with direction or with others? What is your budget? How much time do you have to devote to language study, and how fluent do you wish to be?
If you decide to complete your language instruction with interactive study, either obtain a tutor (or tutors if you can't find one who speaks both) or enroll in two college courses.
Purchase Greek and Latin dictionaries (the English-to-Greek and English-to-Latin kind).
Purchase SparkNotes SparkCards Greek and Latin vocabulary flash cards. Practice reading these cards whenever you have a spare moment.
Alternatively, purchase audio CD courses if you've decided to do self-instruction. These courses enable you to hear native Greek and Latin speakers so you can learn pronunciation.