the best way to get started with getting your audio out to games companies, is to supply audio to indie developers and mod teams. this will get you experiance in working with the perticularities of games, and games designers, and help you build up a portfolio.
the best way i think to start doing this, is to first find hosting for your audio. filefront will do. put your audio up in zipped groups (engine sounds, ambient pads, stinger hits, looping musical beds, etc.) specify a licence type. (creative commons non-commercial types are a good idea) then go to places where games developers and modders are,
etc etc, and post a thread politely advertising your sounds for download and use.
if your work is good, it will get used, you will build a reputation, and people will start approaching you to do specific work.
if your work is not to a good enough standard... well it wont get used, and you wont be approached to do work.
i hope this is of help