Aimini.net is a pretty good site.
mp3raid.com
Reverb Nation and Last.FM are good sites to download free Hindi songs. Download Hindi MP3 is another good site to download Hindi songs.
songarea is a good mp3 download site. you can also convert songs from youtube into mp3 format with some conversion sites like zamzar or video2mp3 for free.
A great and free website I found that converts mp4 to mp3 is called www.converterlite.com. They have different options of what you can do and it is simple and easy to download.
www.limewire.com is a good website
The best mp3 download site is MP3 Mania. They can be found online and have a wide variety of songs and genres to choose from. They have good reviews and users give it 4.5 out of 5 for service.
123musiq.com
There is no online site that edits MP3 files, but you can download Audacity and edit MP3 files for free.
www.heepz.com
beemp3.com
Type in: Example: 'Hangover mediafire' and click the first link. If it is an mp4 or mpg, dont download. But wav or mp3 is good
You can find the mp3 download of Gratis by Babasonicos at shops such as Amazon, this site offers may mp3's for downloads. It is also available for download on Last FM.