Writing stuff that makes people laugh is never easy; humour is such a personal thing, and what is hilarious to one person can leave another stone cold. (The Americans, in case you haven't noticed, insist on spelling it humor; which doesn't make it any easier to write -- just shorter.)
Furthermore, if there is one thing harder to achieve than writing a funny book, it is writing a daily or weekly (non-fiction) column that achieves the same thing. Think what it must be like: you wake up one morning with a hideous hangover, and not only do you you have to go to work but you have to be funny as well.
Perhaps it's my imagination, and I certainly haven't done a statistical analysis, but I have the impression that the Americans have always been better at the ho ho ho stuff in journalism than have than the English. And if I had to pick the best of them all I would go for Art Buchwald. Having said that, Erma Bombeck would be a close second.
I was reminded of all this the other day when I had some contact with Tim Bete. Tim writes a column on parenting for various US outlets, and he is also the director of the Erma Bombeck Writers' Workshop. More to the point, perhaps, Tim is the author of a book entitled In the beginning, which brings together some of his columns. As you would expect, the material deals with the problems of bringing up kids, and has attracted some enthusiastic reviews.
Should you be looking for a present for someone struggling with the changing of diapers (nappies if you're English), your problem is solved. At present it is not available on amazon.co.uk, but no doubt amazon.com can send it wherever you wish.