Look on your local craigslist or college campus for ads pertaining to someone wanting to learn English. These could be ads where someone is looking for a language tutor or a language conversation partner program is looking for a volunteer. Make a note of all the ads that interest you.
Call the numbers you took down and find out what services the posters were looking for. If the ads were for individual English students, find out what other languages they speak. If they do not speak any English, you will need to speak their language in order to give them advice about speaking English. If the ads pertain to conversation partner programs, sign up as a conversation partner in English and any other languages you speak.
Set up a meeting or phone consultation with your conversation partner or student. Ideally you should hold your meeting on a college campus, where libraries and books are easily accessible. This will allow you to show your student or conversation partner how to use dictionaries and encyclopedias.
Assess your student's or conversation partner's English ability. Determine whether the students understand the basics of English grammar and diction, and where they need to go next to take their language to the next level.
Point your student or conversation partner in the direction he or she needs to go to improve his or her English. If you are an accredited ESL teacher, perhaps you could propose that the person sign up for your services. Otherwise, recommend that the person sign up for ESL courses and instruction appropriate for his or her level of proficiency.