If you have a sound card that supports a CD-ROM or SCSI interface, the Linux SCSI HOWTO and the Linux CD-ROM HOWTO have additional information that may be useful to you.
The Sound Playing HOWTO describes how to play various types of sound and music files under Linux.
The Linux SoundBlaster AWE32/64 Mini-HOWTO describes how to get a SoundBlaster 32 or 64 card working under Linux.
Programming information is available from the 4Front Technologies web site at http://www.opensound.com/pguide.
The following FAQs are regularly posted to the Usenet newsgroup news.announce as well as being archived at ftp://rtfm.mit.edu/pub/usenet/news.answers:
The FAQs also list several product specific mailing lists and archive sites. The following Usenet news groups discuss sound and/or music related issues:
A web site dedicated to multimedia can be found at http://viswiz.gmd.de/MultimediaInfo/. Another good site for Linux MIDI and sound applications is http://sound.condorow.net/. Creative Labs has a web site at http://www.creaf.com/. MediaTrix has a web site at http://www.mediatrix.com/.
The Linux mailing list has a number of "channels" dedicated to different topics, including sound. To find out how to join, send a mail message with the word "help" as the message body to firstname.lastname@example.org. These mailing lists are not recommended for questions on sound card setup etc., they are intended for development related discussion.
As mentioned several times before, the kernel sound driver includes a number of Readme files containing useful information about the sound card driver. These can typically be found in the directory /usr/src/linux/drivers/sound.
Information on OSS, the commercial sound driver for Linux and other Unix compatible operating systems, can be found at the 4Front Technologies web page at http://www.opensound.com/.
The Linux Software Map (LSM) is an invaluable reference for locating Linux software. Searching the LSM for keywords such as sound is a good way to identify applications related to sound hardware. The LSM can be found on various anonymous FTP sites, including ftp://metalab.unc.edu/pub/Linux/docs/LSM/ (formerly known as sunsite). There are also various web sites that maintain databases of Linux applications. One such site is http://www.freshmeat.net.
The Linux Documentation Project has produced several books on Linux, including Linux Installation and Getting Started. These are freely available by anonymous FTP from major Linux archive sites or can be purchased in hardcopy format.
Finally, a shameless plug: If you want to learn a lot more about multimedia under Linux (especially CD-ROM and sound card applications and programming), check out my book Linux Multimedia Guide, ISBN 1-56592-219-0, published by O'Reilly and Associates. As well as the original English version, French and Japanese translations are now in print. For details, call 800-998-9938 in North America or check the web page http://www.ora.com/catalog/multilinux/noframes.html or my home page http://www.pobox.com/~tranter.