Since I spend a lot of time watching the election myself I thought I'd sum up a few articles on the fast-approaching election.
Short intro to the candidates:
Ahmadinejad - you all know him and he wants a second term
Mousavi - Ahmadinejad's main opponent, was prime minister in the 80s and is somewhat reformist, has the support of former president Khatami
Karroubi - Reformist, probably the guy Daily Kos people would like the best but has less support than Mousavi and the question is whether he'll drop out to support Mousavi before the first round
Rezaei - more of a hardliner than Ahmadinejad, former commander of the revolutionary guard. He'll probably just take votes away from Ahmadinejad.
Ahmadinejad
Ahmadinejad denies he was behind Facebook being blocked in Iran
Iran conservatives divided on backing Ahmadinejad
Mousavi
Article on Mrs. Mousavi - she is campaigning with him, something that just doesn't happen in Iran. Do a search for "Iran's Michelle Obama" to find more articles on her.
Potential voters warming up to Mousavi
Khatami holds rally for Mousavi
Mousavi's first election speech on tv (all in Persian)
Video on Mousavi (English)
Facebook group for Khatami supporters that will vote for Mousavi
Karroubi
Karroubi not impressed with Facebook ban
Overview of Karroubi and the role of the underdog in Iranian elections (article from ten days ago)
Rezaei
Rezaei vows to end foreign presence in region
Rezaei promises to give salaries to housewives
Other
High turnout = better chance of ousting Ahmadinejad
Facebook unblocker for Firefox (haven't used it myself so can't vouch for it, but have seen links to it online such as here