The Absolute Sound has published a crash course on DSD Downloads.
Read the complete article by Vade Forrester here - http://www.theabsolutesound.com/articles/the-abcs-of-dsd-downloads. 

Featured DSD Download Sites:

Blue Coast Records (bluecoastrecords.com). Operated by renowned recording engineer Cookie Marenco.

Downloads NOW! (downloadsnow.net). The sister site of recording engineer Cookie Marenco’s Blue Coast Records.

Blue Coast Records also offers a helpful Web site called DSD-Guide.com, with lots of very valuable information about DSD recordings.

Channel Classics Records (channelclassics.com). Classics has several major artists in its stable, including conductor Ivan Fischer and violinist Rachel Podger.

Cybele Records (cybele.de). Cybele offers mostly classical music, with an emphasis on contemporary classical music.

DSD File (dsdfile.com). This Swedish Web site sells downloads of Opus 3 and Fidelio recordings in DSD64 and DSD128 formats.

2L (2l.no). 2L offers a wide variety of high-definition downloads, including DSD64, DSD128, and Digital eXtreme Definition (DXD) FLAC downloads 352.8/24.

High Definition Tape Transfers (HDTT) (highdeftapetransfers.com). This company uses open-reel tapes as masters for HD downloads, which include several DSD64 and DSD128 albums.

Highresaudio (highresaudio.com). German download site, some albums are restricted from downloading in the U.S.

Premonition Records (premonitionrecords.com). Offers only one DSD download: a recording of Patricia Barber’s companion album.

Acoustic Sounds (superhirez.com). This Web site was opened up just to handle DSD downloads.

HDtracks (hdtracks.com). By the time this reaches you, HDtracks should be selling DSD recordings along with its other download files.

iTrax.com will offer DSD downloads if the original recording was recorded with DSD. It will offer DSF and DFF files in DSD64 and DSD128 in both stereo and multichannel. Look for iTrax to offer DSD files within 12 months.

eClassical.com will offer DSD files, but it’s not its first priority (that’s multichannel), so it’s not clear when DSD downloads will be available.