CIDIM:

The National Italian Music Committee (CIM-UNESCO) has a web page with useful news for musicians and music lovers.

Concentus Musicus Italiae:

Italian and Russian artists agent.

Edumus

The Italian music educational network. In Italian.

The Prokof'ev Archives:

by the University of London, Goldsmiths College.

Piano on the net

About pianoforte...

The pianist guide to the Internet

everything you need: links, sheets, music search engine...

Swenson's piano shop

this page contains also information of not only commercial relevance

The piano page

another comprehensive piano portal

Mutopia

The "Project Gutemberg" for music scores. From here you can download a lot of free music scores. 

Bakitone International
  Music Competitions

Huge piano resources repository, endorsed by Vladimir Askenazy.

Piano-net

updates another list

Polish Music Reference Center

at the University of Southern California keeps track of  almost any polish or Chopin-entitled competition

Piano page

another list

U.K. piano page

mantains a list of U.K. and international competitions

The Frederick Chopin International Piano Competition

The Home Page of the renowned prize