Since it’s a major match, many different channels and streams will be carrying the game.
A good aggregate site that will host links to different stream formats (flash, WMP, Sopcast, TVAnts and Stream Torrent) is this: myp2p page for LFC V Arsenal
Beyond that, I prefer to watch on a couple of different websites. IraqGoals.tv will have the game for sure on one of their many channels. For those of us who do not speak English as a first language, there is a possibility of a simulcast channel that has the game in a different language; however, there is no guarantee.
Sky Sports HD 1 will be carrying the game in the UK and ROI. You can find streams of SS1 at these links, most of the time:
http://www.soulssports.net/ (iffy stream, off hours it will have SSN)
http://www.livevss.tv/channel1.html (have a good pop-up blocker, this site is annoying sometimes)
http://www.everythingon.tv/viewChannel.php?channelId=2 (24/7 stream of SS1, 2 and 3 available)
Depending on your choice of commentary, Fox Soccer Channel HD will be carrying the game in the United States. They will have links on myp2p as well that you can check out.
Enjoy the game tomorrow (while I have the luxury of moving to a new apartment), and always remember, YNWA