Start with the Alphabet :) http://www.youtube.com/watch?v=4U6876EZff0

The same way you learn other languages!

Here's some useful links: www.livemocha.com and www.internetpolyglot.com for vocab, sometimes there's mistakes, so careful, but the audios and pics really help. You can use Mandarin as a base language there, of course! Be very careful with grammar, it is a little hard, and the fact that the Greek and not Latin alphabet is used may take a little time getting used to.There is a lot of material for the Greek language online, but you have to be somewhat advanced for that, I'm afraid...

1. Eat Greek food! 2. Try living with your parents until you are 40. 3. Drink lots of Greek coffee. All these are essential preconditions to REALLY understand Greeks!