Personally, I have 3 websites which I visit everyday, in a frantic scour for new music to add to my playlists. I have playlists, playlists everywhere. But let's not get into that. Anyways, the first website which is the most common, is YouTube. I know people always say "OH THERES NO GOOD MUSIC ON YOUTUBE, IT'S ALL JUST VEVO AND VEVO SUCK!!!!1!!!!!!!" Well firstly, Vevo don't suck. They have their ads on videos so that we can continue to watch YouTube videos for free. They are what keep the internet economy going. And secondly, all you need to do is know who to subscribe to.
My personal favorite uploaders are:
MrSuicideSheep ( http://www.youtube.com/user/MrSuicideSheep ) for his amazing chilled out uploads. People get annoyed at him for uploading songs late, but who cares? At least he's uploading quality songs.
ElectroBootlegMusic ( http://www.youtube.com/user/ElectroBootlegMusic ) Some of the best Electro Mixes I have ever heard! Also, he uploads heaps of 80 minute mixes, which are awesome for long car rides, walks, runs etc.
Watchterberg ( http://www.youtube.com/user/Wachterberg ) For his beautiful Progressive House series; Sunset Melodies. The title describes them perfectly, watching the sunset and listening to them is an amazing exeperience. And I'm a big fan of Prog House, so I have all of these mixes, and they just have a really happy vibe.
And finally; BizzEpicMusic ( http://www.youtube.com/user/BizzEpicMusic ) for his top notch uploads! Dubstep, electro, all the good stuff, y'know? He uploads heaps of songs which are new, and some that are old, but never really got big.
My second favorite place to find music is Newgrounds. Head over to the audio portal, and there are HEAPS of songs, available for FREE downloads (it's legal, don't worry!) from the artists themselves. I also try to donate to some of my favorite artists on there, such as xKore, but buying his EP. I definitely reccomend heading over to Newgrounds and checking out their awesome Audio Portal!
And finally, Soundcloud. Oh yes, it's not as good as the other two in my opinion, but it's still one of the best ways to find new artists and music. Definitely check it out if you haven't already, make an account and start following all your favorite artists!