Here are some useful programs for decoding SSTV, CW, and the digital modes. Only freeware and shareware Windows programs that use your sound card are listed for now, but a section for programs using the infamous "Hamcom Interface" will be added soon. Also, links to study and practice software are on their way.
CW (Morse Code)
CWGet - A shareware program that decodes CW via your sound card. One of THE BEST CW receiving programs out there! Page also includes detailed instructions on how to use the program.
CWType - A freeware program that allows you to send CW with your keyboard or paddles connected to a joystick or LPT connector. Controlling of the transceiver is done through one of the COM or LPT ports.
DX Cluster Monitoring Software
DXSoft Cluster Monitor - Beta software that displays DX spots using the OH9W/OH2AQ web-cluster.
DXMon - A GREAT program for monitoring the OH9W/OH2AQ web-cluster. Features include automatic updating, UTC time retrieval, and the ability to set alarms based on certain calls or prefixes.
Multi-Mode Decoding Software
HamScope - A freeware (?) program that decodes PSK31 (BPSK and QPSK), RTTY (with the MMTY engine), ASCII, MFSK16, and CW. Doesn't do very well decoding CW, but works great on the other modes.
WinPSK - A freeware program that only decodes PSK-31, but does a very good job of it.
Radio Teletype (RTTY)
TrueTTY - A shareware program that decodes RTTY. Also decodes ASCII (7 or 8 bit), PSK-31 (BPSK and QPSK), AMTOR-FEC (SITOR-B and NAVTEX) SELFEC SITOR and HF Packet (AX.25) is also possible.
WinOrbit - A great freeware satellite tracking program. You can track up to 40 satellites simultaneously, and can create your own maps to use in the display
Slow Scan Television
MMSSTV - A free program that uses your sound card to transmit and receive slow-scan television.