First of all a forum I've subscribed recently, Piano Street. Very friendly community of pianists, professional and amateur that share their views, concerns and ask questions to the community! There is also the possibility to upload videos and get feedback in the "Audition Room". It makes me really happy to see that so many people enjoy music and specifically piano, and how despite the distance we can help each other and share. (My user name is maitea if you want to find me there. )
Youtube is no longer something none really knows about.. Moreover is something most of us would not be able to deal without! But it's barely 8 years old! Obviously as in the preceding paragraph, many young musicians use it to upload their work. Some have grown into "superstars" thanks to it, like Valentina Lisitsa, but also, thanks to the generosity of many "donors", we can see/hear, wonderful material that would be otherwise quite difficult to access to! Recordings of Cortot, Casadesus, Novaes, Yudina.. and so many more!And two of my favourite findings: Rubinstein teaching Chopin 1st Ballade and Gyorgy Sebok, whom I've only "met" through youtube, but I consider a profound inspiration. There was a documentary of his online, but I seem not to be able to find it now.
Other common and incredible resources are Spotify (although not free anymore) or imslp! (What would I do without imslp, I really don't know!) However my last mention (I've always been told, three is the magic number), so my third and last reference is to Skype! Not that obvious at first right? Well, after few requests of former students no longer living in the UK, I gave my first lesson through Skype some days ago! And hey! It was quite a success! As I explain in the teaching page, it is not the same. By definition, it can't be. But it also works, and depending on the needs, interests, availability, then it might be what works.
So, despite being an analogical musician I'm tuned to technologies ;)