We have two kids--one is two and a half, and the other is eight months old. Best thing that's ever happened to me, but you have no idea how much it will change your life until it actually happens to you. Overall, you don't mind much (or even notice) because you are so totally in love with your kids (you also can't grasp that until it happens to you), but there are definitely some difficulties. Day care is fucking outrageous--we pay $1200 a month, and overall I'd say our children cost us a total of nearly two grand a month. That's a lot of cheddar for a couple of social workers in Louisville. As far as time for hobbies goes, I'm lucky, in that I get to listen to music most of the day at work. My wife goes to bed early, so I spend a couple hours a night on the computer, listening to music, writing reviews, etc.
I'm turning 35 this month, so we're definitely in a good place age and experience wise to start breeding. Best of luck to you.