A Damsel In Distress is a typical Wodehouse work: light, fun, and endlessly entertaining. Several of the characters are familiar Wodehouse types: Reggie resembles Bertie Wooster in many aspects, Belpher and its denizens call Blandings to mind, and Keggs is a slightly less benign Jeeves. As in most Wodehouse novels, there are no truly bad people- just unpleasant ones with competing interests. Even Lady Caroline, snobbish and dictatorial, turns out to have been right about Geoffrey. Percy is, of course, an unpleasant person, but his faults lead him into so many hysterical disasters that it's impossible to truly dislike him. On the contrary, the parts of the novel which center on his misadventures are some of my favourite bits of the book.
A Damsel In Distress is good gateway Wodehouse: an excellent book to start with if you've never read his works before. Unlike the Jeeves & Wooster stories, or Blandings, it's a stand-alone novel, so you don't have to worry about it referencing events or characters from earlier works. This was one of the first P.G. Wodehouse books I read, though not the very first, which was Hot Water. I was hooked from the first.