Start simply. Even if you are helping someone who is older than you are, you need to choose reading material that is appropriate for her reading level. Starting off too ambitious, with complex articles or literature, will demotivate the person and make her feel like reading is difficult. If you are unsure of the person's reading level, start off with something that is easy, to get off on a strong foot. Maintaining motivation is key in helping someone improve her reading.
Read aloud. With difficult texts, you should always read first to let the person hear the correct pronunciation and flow. Take turns reading paragraphs or pages, and have the student read aloud after you. Hearing the person read will allow you to be able to correct and make constructive criticism.
Create a vocabulary notebook. Have the person write down all new words and include information such as the part of speech, common usages, synonyms, antonyms and an example sentence. Writing down new words and using them in context improves overall vocabulary and reading comprehension.
Have discussions. Talking about what you read together is the best way to improve reading comprehension, while at the same time sparking an interest in the material. Prepare questions or discussion topics before your reading sessions to facilitate discussions.
Schedule regular reading sessions. If you really want to help someone learn to read better, part of your job is keeping him motivated and committed to improving. Choose a location and time that is convenient for both of you with a quiet atmosphere where you can get work done.
Find interesting foreign movies with subtitles. This is almost a "trick" to improve reading, particularly if you can find a foreign movie that is of interest to the person you are helping. Following subtitles helps improve reading speed and comprehension, under the guise of watching a movie. Choose a spot with a TV for one of your reading sessions, or bring a laptop computer so you can watch a foreign film together.