I am an avid user of
Youtube, back in the beginning of the fandom i used to check new releases AND favs/likes of the people i followed, and now i am following... (checking) 999 different channels (mostly music ones), it is not anymore doable to follow the favs/likes but it still massive enough to provide loads of fresh releases (maybe a bit too much) in the "/feed/subscriptions" panel of YT.
So it's mainly YT, and to compensate the lack of newcomers and discover new tracks, i started to use
Twitter a bit (Everfree Network and MLP Tunes accounts are handy),
Soundcloud (but i am bit afraid that i should pass through the same "following gather" i did for YT to make Soundcloud effective, at least the "embedded share" option (similar to "retweet") is interesting...), and more recently a bit of
EQD musical news.
On top of this, i am starting to use some archive / listing websites for pony music, like
pony.fm,
Eqbeats and
EQD Music... and i recently found
Brony tunes too, dunno about the last one but 3 first ones can be handy to expand some researches (btw all of them have incomplete databases in terms of quantity
(they lack a lot of songs, due to the amount of work needed) and quality
(a lot of songs are terribly tagged)).
Edit : and i forgot
bandcamp, where i bought many albums... but it was linked by artists through their YT/twitter.