Constant Content

I just want to know, if I sell a document for full right's or unique rights, can I not publish or use the document myself in the future? Basically, is it no longer mine?

That's correct, although with Unique Rights, the buyer is required to keep your byline and make no changes to the article. So if he uses it on his site (or anywhere online), you can include it in your portfolio/resume. If an article sells Full Rights, you're basically giving away all rights to it (you're a ghostwriter) and the buyer can do whatever he wants with it (and you can no longer claim ownership to the article). If you want to be able to use your articles yourself, you can sell it here for Usage Rights only.

So if he uses it on his site (or anywhere online), you can include it in your portfolio/resume

Clarification: You can include a LINK to it if you're using an online portfolio/resume (don't copy and paste as it could turn into duplicate content). I believe printing a copy is fine for physical portfolios.

Thanks, Celeste. The link to the article was what I meant when I said you can include "it' in your portfolio/resume, not the article itself.