How-to Multilingual WordPress Site English / Welsh

Hi WordPress Community,

Looking for abit of advice, i’ve been asked to put together a Multilingual WordPress Site for English / Welsh users. I don’t need the content translated, the client is going to do that themselves – Could anyone give me the best way to achieve this / Some examples of your Multilingual WordPress setups.

* Is there a dedicated plugin for this?
* Is it just a case of using custom content types and calling them depending on which language is selected?

Thanks in advance!