Learning in a classroom, especially from a native German teacher, is a good way to start learning German. The teacher will start you off learning grammar, vocabulary and pronunciation; German and English use the same alphabet, but many of the sounds are different. A classroom environment helps students by requiring homework that will be used in classroom activities and tests. Classroom activities are helpful for practicing all aspects of the language, with the teacher supervising and correcting where necessary. Private tutors are very helpful because it allows the teacher to see what level the student is at and teach accordingly. The Goethe-Institute is worldwide German school that offers all levels of classes.
Thousands of internet sites offer very helpful resources such as printable lesson plans with answers, interactive lessons, lists of the most used German words, vocabulary words arranged in specific groups and short cuts to understanding German grammar. There are many good German textbooks available in bookstores and online, such as "German Grammar Drills" and "Schaum's Outlines of German Grammar." If you want to listen to lessons, try CDs such as "Drive Time German" or CDs from Berlitz. Another helpful aid is a good dictionary, especially an electronic one. Get in to the habit of using it to translate everyday words and even writing these words in a small pad you can carry with you.
Movies and magazines are an enjoyable way to hear the German accent, pick-up expressions, see how the language is really used and test yourself on what you have already learned. Once you have reached an intermediate level, try watching German movies with German subtitles; the movie will give the words context, making them easier to understand while testing your proficiency. You can find German subtitles online for almost all English movies and TV shows. This will help you pick-up more of the expressions and colloquial language.
Once you have a few of the basics of German, try to find some native speakers in your community; visit German restaurants, community centers, German schools and universities where there are visiting students. Make some German friends, speak to them in German and ask them to help you with your accent and to correct you when you make a mistake. Join German chat rooms or exchange emails with native speakers. This will force you to use and hone the German you know and to learn words and expressions you don't know.