Twitter is blowing up with news of tear gas, water cannons, and shootings in Tehran, at today's demonstrations. This is what the protesters are dealing with now.
Watch the #iranelection, #iranelections, and #gr88 hashtags if you're on Twitter, and be careful, not everything is reliable.
Don't trust any news coming exclusively from Iranian government/state TV -- not even if you see those reports repeated on CNN. Until it's verified by an independent source, it's possible that the government is fabricating some stories to justify a harsher crackdown on the demonstrations and incite anger against the protesters.
Reliable Twitters at this time are:
@ProtesterHelp@Change_for_Iran@persiankiwi @voairan@AnnCurry of NBC is doing really good work. Her twitter's been useful and reliable.
CNN is... still disappointing but it'll do in a pinch (to be fair it's difficult for them to report live from this) -- if you can catch the BBC or Al Jazeera you're a little better off.
Huffington Post is liveblogging the uprising here.
New York Times is liveblogging it here.
Andrew Sullivan is still liveblogging it and doing some of the best work I've seen from an individual blogger.
ontd_political's latest live thread is here.
You can see video at most of these sources.
ETA: Google Translate has just added Persian (Farsi) to their service. You can use it to translate text that you may find at websites and on Twitter to English.
Please keep the protesters in your thoughts/prayers. I'm in awe. Many of them are so young, and they're so much braver than I could ever be.