The LiteOn F.A.Q. - http://club.cdfreaks.com/showthread.php?t=109986
A must-read for people unfamiliar with LiteOn optical drives.
The Firmware Page - http://forum.rpc1.org/portal.php
A great place to start when looking for firmwares and firmware-related things. The firmware collection is massive, and the forums are great resources.
CD Freaks LiteOn Forum - http://club.cdfreaks.com/forumdisplay.php?f=44
This is probably the largest and most active LiteOn community on the Internet. There are a lot of LiteOn-related resources here.
LiteOn Tools Collection - http://club.cdfreaks.com/showthread.php?t=83441
This is a useful resource created by Ssseth over at CD Freaks. As the name suggests, it's a collection of LiteOn-related tools.
dhc014's Page - http://dhc014.rpc1.org/
dhc014 maintains a large collection of LiteOn and rebadged LiteOn firmwares. You will also find useful firmware flashing resources here.
digi's Page - http://digi.rpc1.org/
digi maintains a pretty nice resource page for LiteOn DVD-ROM drives, in addition to resources related to region-freeing and firmware flashing.
ala42's Page - http://ala42.cdfreaks.com/
ala42 is the author of the very useful MediaCodeSpeedEdit which is an OmniPatcher-like program for non-LiteOn drives.
No-Frills Links to Official LiteOn ODD Firmwares - http://codeguys.rpc1.org/lofw/
Easier way to access the LiteOn firmware than using LiteOn's site. It also list the firmware in release order so the latest releaes can be detected more easily.