Well as to who he is and what does he do, here is a blurb from the 'About the Author' portion of one of his novels.
"Since he began writing professionally in 1972, Spider Robinson has won three Hugos, a Nebula and numerous other awards, and published 28 books, eleven of which involve Mike Callahan and his family and friends."
It doesn't tell you much other than he is a successful writer. The best way to describe his work is hopeful optimism, spiced with intelligence, humor and technology served up in a friendly bar where all drinks are a dollar and puns are rewarded.
I love his books because they make me think, they make me laugh and they make me wish I could go for a visit and stay for the rest of my life.
The Mike Callahan books center around a bar, Callahan's Place where everyone is accepted, no matter their flaw, their planet of origin or their bad puns. The people who gather there work out their problems together. Together is the key word. Every character introduced has had some sort of tragic happening in their life, or is just plain odd like the Lucky Duck who happens to be the offspring of a Pooka and a Fir Darrig who tends to make the laws of probability do strange things around him. The narrator, Jake Stonebender, lost his wife and child when the brakes failed on his car; the brakes that he was too cheap to have an expert change and did himself. Then there is a whole cast of characters who each have their own little quirks. I could go on for hours about Doc's puns or Slippery Joe and his two co-wives, Ralph van Wau Wau the talking dog...well you get the picture.
Just taking it as plain humor, popcorn reading - it's a blast. A fun, scifi lite story of friends getting together, having a great time and ending up saving the world. However, if you really read deeper in, Robinson has a lot to say about what is wrong and what is right (like God's Blessing - Irish Coffee) about our world today. I find his writing to be extremely intelligent and well-thought-out. I would recommend it to anyone with a sense of humor.