The easiest way is to live in a Spanish speaking country. Seriously. That's how I learned.But you are in Germany.And the other option are to buy boooks or learn online and I would recommend Pimsleur over Rosetta. I have used both to learn Portuguese and find the Pimsleur method to be superior. It concentrates more on actual conversations while Rosetta goes more towards individual sentences or words. However, both methods offer a very comprehensive package to get you started. Along the way you will need some books on grammer as Spanish tenses are much more complicated than in English. Ditto with pronouns. I have listed a site below which offers both courses at a substantially reduced price. That means they are selling you copies they have run off on their computer. Or you can get them for free by looking around the bit torrent sites. Buena suerte.



Take a look at:
http://www.bbc.co.uk/languages/spanish/
http://spanish.about.com/
http://in.youtube.com/view_play_list...&v=YA8DybfLsOQ
http://learnspanishreview.net/LearnSpanishCD/