In no particular order
  1. Immersion
    Living in a country where they speak the language paired with classes (ideally focused on grammar) is really the best way.
  2. Phone app
    Duolingo (limited options but so awesome), human Japanese, 7 Jours, and tons more
  3. Rosetta Stone
    I don't recommend it. Possibly good for some learners but I'm not a fan.
  4. Formal class
    Universities, community centers, etc
  5. Podcasts
    I've listened to Arabicpod101 and they have many others with the same title format. Frenchpod101, Japanesepod101 etc.
  6. Conversational meet ups
  7. Tutor
    There are many ways to find a personal tutor. is one example. Most will provide a deal for multiple students at once.
    The best (single word) translate website/app there is. If you can't find your answer, there are extensive forums. Not exactly a way to learn a language but it can be an INCREDIBLE tool along the way.