Are you thinking about buying a puppy? Have you already chosen a breed that fits your lifestyle, or have you just seen a dog you find "cute"? Here are a few links to help you make the right decision:
Animal Protection Switzerland - checklist for buying a dog
Puppy development phases: This article also addresses the topic of neutering. Personally, I think it's a difficult topic, and every dog owner has to deal with it. I had Flocke neutered after her first heat. Why? After her heat, intact male dogs were very pushy, and she felt very harassed. So I made the decision and haven't regretted it.