Discover the Greek Language
If you're learning Greek you may very well want to get an overview of the language, some of its unique features, geographical information about native speakers as well as loads of information on grammar, linguistics, history, diaspora and general language structure.
All of this and more is available in Wikipedia's Greek entry. There are also some interesting links at the bottom which take you to further resources to explore and learn about the language of Greece.
Don't Miss the Greek Category Page
Also related and useful is the Wikipedia category for the Greek language.