libre.fm is a pretty neat service overall but there is just a slight problem you should be aware of before you submit any of your music to it.
You won't be able to edit album covers or song URLs, or delete a song/album if you somehow make a mistake when adding it, or make an accidental duplicate somehow.
This discouraged me for a bit because there was very little dedicated to libre.fm on the internet really, and when I found and checked the bug tracker and blog and the couple of other things there were it seemed like development and bugfixes had kind of just halted for the moment, and this issue wasn't really going to get fixed.
But the good news is, it is going to get fixed. The plan at the moment is apparently to implement some way that incorrect albums and such will redirect to the correct ones.
And also, if you ask in the IRC, there is at least one person there who has access to the database and can correct any duplicates you added by mistake. The thing about the IRC though is that qwebirc is not a very good client and may boot you out if you don't stay on the IRC tab all the time (and I'm not even sure that would work; it seems to be pretty adamant about booting you out). I'd recommend installing an actual program like xchat if you want to use IRC. xchat works pretty well if you have linux; I don't know what to install for Windows or Mac, though xchat supposedly works on Windows too.
So... if you have duplicates or such on your artist page and can't stand it, don't fear, there is hope. But if you don't have any yet, I'd recommend being very careful when adding new tracks. Be sure to pick an image URL you'll be able to access for a long time, such as one you upload to the same archive.org page as the song. That's the way I'm doing it now.
I thought I should post this because this was basically the information I was looking for when I got myself stuck with a bunch of duplicates, and it really wasn't anywhere to be found.