is his official site. You can also find his tweets in my pan-Libertarian twitter channel, https://twitter.com/brainouty/lists/libertarian
He's the youngest and yet most traditional of the candidates, strict Constructionist, calls himself prolife but wants no law on it -- as any Libertarian shuns regulating ANY social standards. So they're like the Democrats in that way.
But like the Republicans, in that they are fiscal conservatives, meaning priority given to even dismantling Federal Agencies (if Congress will agree), so severely pro small government and states' rights.
If you read Petersen's too sparse or very succinct site, he's a tad more radical than I expected. He's said he's more pro-Israel, but the site doesn't reflect that.
Libertarians are big on non-involvement. That troubles me, esp. since the only way to keep terrorism from our shores is to take the war to the terrorists. But, no one agrees on everything.