Hi Bruna, welcome to the EE Forum.
I am on the intermediary level, well...I am being being a bit pretentious perhaps?okay I am on the basic level so...
I am not an expert on the subject, just a dilettant with an opinion.
If I were you, and I had some time on my hands (maybe) I would adopt theExploring Through Writting by ANN RAIMES, St. Martin Press New York
or Writting and Grammar
- and/or Communication in Action by Ruby Level Handbook Edition, Prentice Hall press.
Those are books designed exclusively to hone the writing skills. Could be other books on the subject. This way, you could have an overview of the topics you could explore, I mean comparing with your pupils´needs. Something to begin with.
If the learners were ESL, I would say that a kick-off could be something like this:http://www.breakingnewsenglish.com/1206 ... germs.html
And others sites focused on health/medical terms, perhaps the Health/Technology sections of some newspapers (The Guardian/BBC, to begin with.) could be good to get them acquainted. In Brazil there is the Scielo site, with short summaries etc.
And then, you could make a compilation of your own, taking their levels, skills and knowledge, into account.
But, I leave the ball into the Experts court. This was just one of my random thoughts, for the sake of communication.
You know, sometimes I just can´t help it, as laymen do.