There's actually a couple of options for watching Arrow season 1 with English subtitles.
If you don't mind pop-up ads, I've been watching it on Watch32, but I've only just started so I can't say whether all episodes are actually working. The first three were though, and season 1 is looking great!
Alternatively, you could try out Project Free TV wich has both Season 1 and 2 right here: http://www.free-tv-video-online.me/search/?q=arrow&md=shows
I watched Breaking Bad on there, all seasons, and they worked fine.