List here if you know any free ones?

Yes please, even i need.

Not sure how much of a help this is. But try http://www.mp3powered.com/

It's free for bands to promote themselves.

I also belive it's free to download music from other bands.

Metal Storm has a forum for promoting bands/websites, etc. Also, my other website - www.metalthrone.net has a forum where you can promote your band (or website for that matter). Plus we have a downloads section where you can put a few mp3's if you wish. In your thread you could link your mp3's and everything.

www.myspace.com

www.soundclick.com
www.audiostreet.net
www.garageband.com

hmm, i guess i found one, but I dont know if this can help too much, i''s a good site where I found many good bands as well, but i'm not sure if it's free so I guess you can check it out and look if it works like what you are looking for

http://www.metal-observer.com

Metal Storms very own Promotion and Adds forum, I know i use that a bit
http://www.metalstorm.ee/forum/board.php?board_id=30

myspace is really good. All you have to do is pretty much add stuff to a profile (including songs) so that you look cool and sound good, then go to official band myspace's and request people who are friends of that band so that people can get to know your band. Or request friends, friends of friends, then on and on. If you know don't know how myspace works it might take a while but if you do, then it's easy
One other website is Purevolume.com, it's got some good famous metal bands but it also has alot of pop punk/emo bands

you can send contact Jeff of metalstorm and ask if he can review your cd, then you might have your band on the frontpage of metalstorm for a short while

yeah id say Myspace too

You could try Metal-Archives.com as well plenty of bands big and small on their and no metalcore/screamo shit is permitted either.

What about Metalreview? If you get a good review on that site, you would be getting ALOT of peoples attention.

Metal Hordes is a good place if you play extreme metal.
Finns musicians always have to check this site www.mikseri.net
Of course both of these sites are places to put your songs for sharing. So get on recording!

i'd have to agree with a few people up there, myspace definately. i have found many great bands that i now love thanks to searching around myspace randomly

I write for a website www.hellspawn.be. We write in Dutch and write revies for labels like Century Media, Nuclear Blast, Massacre, Metal Blade, Lion Music, Majestic.... and we support the underground and unsigned bands. You can always PM me...

Myspace

www.last.fm
A very popular music site, you can upload your own stuff for others to hear, and they make it easy to advertise your band/music.

except METALSTORM..?? ;P

Another link

http://metalhordes.com/

Another way: type in your searcher "metal forum", almost every forum got promotion thread.

Well dude, what would recommand is MySpace, Hi5, Facebook ...etc
Those sites are pretty good for such a thing
And i would happily host a section for your band in my website so you can promote it there as well ... if you are interested send me a PM and we will talk about it.
Rock on!