First up. . . Zack's The site highlights earnings surprises, up and down, along with a full menu of earnings summaries and a reporting calendar. Big surprises in the direction of the open can produce some quick returns. They also have a service called Surprise Trader for swing traders with a money back guarantee that's worth a look.
Next is RTT News This site profiles positive and negative pre-announcements along with an earnings calendar and a full report of latest earnings. This is interesting opportunity to trade the rumor and those that bought HMSY and MDAS at yesterday's open and then closed the trades at the first 3 bar parabolics reversal put some quick change in their pockets. If scalping appeals to your trading mind and risk comfort level, this is a fertile site for some quick gains.
Finally, hands down, the best non-technical blog of all time (IMHO) Between the Hedges To even begin a half way fair analysis of this site would require more time than I have. Bottom line, just link over there and delve in. Live upgrades, downgrades, market snapshots, momo stocks, charts, news, performance stats, links to magazines and newspapers around the world (how about the Times of India or the Brazil Post?), video news and more, much more. If you started reading the new material in this blog at 6 in the morning, there's virtually no way you could finish it all by 6 at night, so you've got to be a bit selective about your focus here. A real treasure trove.
This is a late post addition, but deserves a close read. Bepsoke, a site I have mentioned many times before, produced a series earnings season posts on Jan 13th. Scroll down on the Besoke link to catch 'em all.