ChoralNet is a terrific resource. It has its own database of choral music where you can search for information about choral pieces. It also has terrific links to websites with free choral sheet music, Mp3 files of choral groups, and much more.
The Choral Public Domain Library
The Choral Public Domain Library is an archive of printable choral music files that are now in the public domain. In other words, free music for things out of copyright.
The Silvis Woodshed
This site contains MIDI practice files of choral music and was the inspiration for this website. It is a good resource for practicing.
Hear the Choirs Sing
Choirs from all over the world have donated samples of their singing to this website. Use the searchable database to look for a song you want to hear. I recommend searching by the first letter of the title – the site is case-sensitive and there are misspellings, making it sometimes tricky to find what you are looking for. Songs are in several different formats, including streaming and Mp3, so make sure to have the appropriate software on your computer. (See the Useful Free Software Links on the homepage for more help with this).
This site, originally developed to help choral basses learn their parts, now has resources for all voice parts, including midi files, choral links and other great things
John Fletcher’s rehearsal files
John has put together a really extensive collective of practice files for choirs in mp3, midi and Scorch formats. He has offered this for free, but if you can, donate – this is a real labor of love, but emphasis on the word “labor”.
Musica International Database of Choral Music
This site is a reference site containing information about composers, difficulty levels, publishers and sometimes even audio clips and translations of choral works. It is a fabulous site.
Honda Civic Choir
This links to an ad for the Honda Civic. It is a full length choral performance and absolutely wonderful.