Uploading Own Tilesets

I'd like to upload my own my own maps for the use of my campaign (And music too, if that is possible). However, I don't know if this is already a feature. If it is, I don't know how to upload it. Is there a way to do this? Currently, as someone who plans to use pre-made modules, this seems to be a big obstacle.

Nicolas-- when you started your session a nice YouTube video popped up explaining how to do a lot of things as Game Master, including uploading your own map. Since you seem to have missed this, I've queued this video up to the appropriate section: <a href="http://youtu.be/DXXXFsjUDVI?t=2m9s" rel="nofollow">http://youtu.be/DXXXFsjUDVI?t=2m9s</a> At this point all music is through SoundCloud, which you are welcome to upload your music to for use in Roll20. Be advised, the Roll20 search defaults to things tagged as "ambient".