Um, you can't. (Unless you happen to be a nonprofit or a local government, in which case you can find information here.) If someone is telling you that the government is handing out giant sacks of stimulus money, they're probably also eager to tell you about a great new diamond mine in Nigeria that you should be investing in. The Federal Trade Commission has issued a notice about stimulus scams, so consider yourself warned.
I'm actually a little disappointed not to have received any of the scam emails, but thirty seconds on Google digs up websites here, here and here, all of which claim to offer easy access to government grants -- in exchange for a little personal information or a nominal fee. To be sure, the websites look like dusted off relics from the Internet's stone age, with poorer grammar. (One claims to "have
help ten of thousands Americans like you," which inspires little confidence.) And yet there must be some confusion about how the stimulus works, or these websites wouldn't exist.
I bet the confusion about the grants is part of a larger one: people expect the stimulus to start working in big, dramatic ways. (The Government will roll into your neighborhood, dynamite a few crappy schools, and build a fancy new computerized super highway.) But that's not how it's going to happen. The single largest provision of the stimulus, the Making Work Pay Tax Credit, is designed to be inconspicuous. If it works properly, you won't even get a check from the government: your employer will just withhold a bit less of each paycheck for a while.
And I don't think the administration's lineup of websites is doing a great job of clearing up the confusion. Recovery.gov is awfully sleek, but unless I'm missing something it doesn't have any grant application pointers or warnings. (The site's FAQs seem to wander off on contemplative-sounding tangents, like "What is a Fiscal Year?") Grants.gov, meanwhile, looks like a scam website that hasn't been updated since 1997.