Currently there are three flavor of 802.11a/b/g.
n is in progress and soon will be available in the market.
It is a standard for WiFi [Wireless Fidility].
mainly used for creating LAN across a building.
it is a physical layer when we talk about the networking of TCP/IP stack.
so if you know network programming i.e. socket programming then you can write any program to communicate over WiFi.
You can use C/C++/Java on window/linux/unix/solaris/mac platforms.
if you want to program handheld device you can use C++/J2ME.
I hope this clears your doubt regarding 802.11 programming.