Like the others, I'd recommend using VLANs only if you need them to secure something. For instance, in a college where I worked previously, I helped migrate from the stacks of switches that @scottalanmiller mentions to a network using VLANs to separate student traffic from the admin traffic.
You will definitely need a router (or layer 3 switch) or firewall to ensure that the VLANs have access to the internet, but not to one another.