To learn to pronounce words, you must hear them. A good-quality language learning tape series on CD, DVD or audiotape will help. Avoid programs that do not use whole words in context. Listen to language being used in real-life situations
similar to those you will encounter. Keep a journal and write words and meanings of words you hear and understand. When you listen, avoid distractions. Listen and repeat the word out loud, allowing yourself to hear the word as you say it. You can listen to Portuguese radio stations and write new vocabulary you learn. Listen to and sing along with songs from Roberto Carlos in Portuguese. (He also sings songs in Spanish.)
A beginning level conversational textbook is a good investment. Also, get magazines and simple texts that contain the Portuguese language. These texts should be related to the area of Portuguese you plan to use. They could be trade magazines, travel magazines, shopping catalogs, newspapers or websites. By reading materials that you are familiar with, you have a head start in recognizing and acquiring the words as you see pictures relating to them.
Find a native speaker of Portuguese or a more advanced student to practice conversation. Put an ad in Craigslist.com or the local paper. Talk to the professor of Portuguese at a local community college or university to see if he has anyone you can practice with. Do real-life activities with your conversation partner such as go to a restaurant and order a meal. Go shopping at the mall and name items and talk about prices. Find a local church that has missionaries in Brazil. Write to the missionaries and their congregation in Portuguese. If nothing else, change your "self-talk" to Portuguese and practice speaking aloud as you walk or jog. Don't worry too much about pronunciation at first. A correct accent is acquired over time. As long as you can communicate, you are on the way to becoming fluent.