There is a lot of material on youtube. TheNetworkBerg have great series on VLANs. Also there is great topic created by @pcuinite: http://forum.mikrotik.com/t/using-routeros-to-vlan-your-network/126489/246
But as @infabo stated it’s more complicated than solution he proposed. I wasn’t aware of that topic so I didn’t suggest that.
If you want to learn networking or more about RouterOS then this is a good way to learn something but as @infabo warned you, there is great chance that you get locked out of the router. There are steps that need to be preformed before messing with VLANs.
If you want to proceed with VLANs then i suggest you to read topic i linked you and maybe watch some of the videos. Try to config router yourself and if something is not working come back here with config export and we will help you.