A lot of places with music on web. You can search for absolutely free tracks, but it takes really plenty of time to find something suitable (and qualified).
Maybe great solution is using special services called "production music libraries" to quickly find music that fits to any project perfectly?
Well, if you think that way, have a try these pages with music created specially for use in cinema and media.
One of them http://goo.gl/mOF0UC is very professional, but pretty exprensive, honestly, but usually everything is paid off and client are happy,
The second is as you will notice have a VERY low pricing http://goo.gl/nylfL7 But it is not about bad quality, just this site is mainly popular of it`s professionality and lovely prices for all the tracks.
Hope you found this information valuable and I`m looking forward for your thoughts on this services.