This. Also, you need to kick up the quality a bit- game texture and framerate wise. As Kyzr mentioned, there are loads of HL2 Let's Plays already out there. You need yours to be special if you want people to watch it and get interested. Add a twist, like playing it on hard mode using only the...
open port 27015 tcp/udp on your router
open port 27015 tcp and udp on your firewall outbound "search for windows firewall with advanced security in the start menu"
go to the map you want in hldms. let's say the name of the map is cmap0
in the game:
sv_lan 0
sv_region 255
hostname myserver...
WUB WUB WUB WUB WUB WUB WUB WUB WUB WUB WUB WUB WUB WUB WUB WUB WUB
But this video is by far worse than Friday:
http://www.youtube.com/watch?v=7DwT_2QQU64&feature=related