Guest Posting Opportunity, where to put the link?

[lipulili]

I have been asked by a site owner in our niche to publish a guest post in his sites. He will accept one do-follow in the article. So, here is the question where should put the link? Should I put it in the author's bio section? Or, should I find a relevant place in the content and stuff it in with a relevant anchor text. As, I have been doing a lot of reading in this forum. And people are often suggested here that I should make the links more and more relevant.