I had kids at the age of 32 & 34. Don't take Todd's admonition of exhaustion lightly. That's probably the toughest part of it, physically. The fact that your entire life then revolves around your kids (or at least in my household) was something I expected. Fortunately we've had one set of parents around us at all times.
That being said, having kids has been the most fun thing I've ever done. And that includes driving Porsches and riding motorcycles.