The first rule for doing any kind of science writing is an obvious one: don’t try to take on something you really don’t understand at all. Make sure that you’re going for projects which are on or not too far above your level of expertise, since it’s no use trying to explain quantum mechanics if the last time you did physics was in high school.
All the same, there are lots of online sources to help you get up to scratch on something you’re a bit rusty on, and reporting on recent scientific discoveries (for example) doesn’t take a lot of research. Nor will it require you to really go past the basic principles either.
How to Research
To start off, you should probably get an idea of recent developments in the subject. If you’re going to do a lot of science writing, you might want to subscribe to a periodical or magazine that publishes about scientific topics. New Scientist might be useful for a general reader, while Science or Nature might be more appropriate if you already have a good grasp of the basic principles, and if you’re planning on writing more specialized articles, essays and blog posts.
Even without a subscription, there are a lot of free content available on sites like New Scientist, and PLOS ONE is a great source for freely accessible peer-reviewed studies and reports. Google Scholar might also be useful, and don’t forget that if you have access to a library, they might be able to give you access to sites that usually have a pay wall.
Once You’ve Done the Research
It’s probably a good idea to take notes as you research, particularly if you find anything particularly relevant or interesting that would fit into your piece. Keep track of anything you’re going to refer to, so you can link to it. This way, you can show off the fact that you have done research, and you can support your article with facts. Just having a list of references immediately makes your article or essay look well-researched and more authoritative.
When it comes to the style of the article, keep your audience in mind. In fact, all the tips which apply to a normal article apply here, too. Plan it out beforehand to hopefully avoid having to do extra research. A well-planned structure will also improve your article's flow, making it easier to read.
Check Your Work
Scientific writing is the sort of field where you need to be very sure that your information is accurate, and that your explanations are clear enough so as not to confuse the issue. The best thing would be to find someone of approximately the right demographic and ask them to read your essay for you: they won’t be as close to the material, which means they're more likely to spot mistakes, inconsistencies, or things which might confuse the reader.
At the same time, make sure you’re not talking down to your audience. You can assume a certain level of knowledge for any given audience – if you’re writing about a medical advance for the medical community for example, you can assume that the people who read your article will understand concepts like the placebo effect.
Be Prepared to Make Corrections
If someone brings up an error in your work, it’s important to correct it as quickly as possible so as not to mislead readers. Scientific writing is usually not about opinions, but facts. However, it can sometimes be difficult to tell what a theory is and what has been established as fact. You don’t need to keep revising an article with every new discovery, but you do need to make sure it’s correct as of publishing time.