Nice to see you back, Belle!
On proz you have a place where you can post both the original and the translation, so I recommend you do that.
Posting a piece of translated text without source is less effective if the prospective client wants to check your work to see what you are capable of.
oscar mojon saa wrote:
When you have the written consent from your client -the translation agency or the direct client- it is better to show the original together with your translated version. You can even highlight the difficult points in the translation process.
But I think a better idea is to offer a CD with sample translations to all your prospective clients (i.e., in trade shows), or you can get more professional exposure by offering a free copy of your CD to the companies registering at your website.