CPU-way: http://forum.mikrotik.com/t/using-routeros-to-vlan-your-network/126489/1 (it’s a bit extensive, but with pretty good examples and good explanation)
Switch-way: https://wiki.mikrotik.com/wiki/Manual:Basic_VLAN_switching … in particular section “4 Other devices with built-in switch chip” (it’s official documentation, so refrrence information. Examples IMO are a bit worse explained, but should help get things done)