The premise is Sam is an unlucky divorced loser who works as a data-entry drone. He's also the former sidekick of the world's Superman equivalent. When the world's greatest heroes are all killed horribly by an unknown force, he's forced into a government project consisting of three sidekicks recruited from civilian life then given armored super-suits. Unfortunately, well, they're all a bunch of idiots.
Sam is Kid Random and possesses the power to alter reality at will but he can't control what happens so he just makes oddball stuff happen (he's a god with none of the perks). There's Anna, Allergy Girl, who is an alcoholic former heroine with the surprisingly useful power of giving people allergic reactions. Finally, there's Randy who is quite possibly insane but has a useless powe of talking to butterflies.
None of them are remotely qualified to be superheroes anymore and the plan to have them take on the person who massacred the greatest hero team in the world. However, the government doesn't have plan for dealing with the end of the world and clearly didn't update this one very well. The fact they insist on manipulating the "heroes" despite the fact they would have come around on their own is a terrible idea. The humor is sometimes a little too hard on the fact that Randy is a complete lunatic who is trying to be a superhero despite having no powers (and not bothering to develop any Batman-esque skills). Also, Sam's patheticness approaches the Nicholas Cage' Weatherman but these are small complaints as best.
The action in the story is an excellent mix of comedy and (semi)intelligent use of everyone's powers. The heroes are morons, or at least totally inexperienced with their powers, but that has its own benefit given no one can actually predict what they're going to do. As one famous martial artist said, fighting a complete amateur is often more dangerous than someone who actually knows what they're doing.
I also really enjoyed the villain and the revelation about his motivations as well. The entire concept of the sidekick as a child being carried into battle by adult superheroes has not aged well. This satire of them works well despite it. Yeah, it may make the original superheroes look terrible but that just shows why the Sidekick Initiative is all the more heroic.
The only real complaint I have about the book is the character of Kapitain Nazi, who was apparently a brainwashed political dissident who became a Nazi supersoldier and murdered thousands of innocent people in ridiculous ways. He's meant to be a character who everyone acts like he should be irredeemable (and may be) but I think making him a (former?) Nazi was a bridge too far.
So I very much recommend this book.