This post is a work in progress. If you have any suggestions, I'd love your help. Post in the suggestions thread if you've got something to add.
I believe that to make respectable posts and to avoid making a fool of yourself in the Science, Tech, and Math forum, it's best to have some basic literacy in Science and Math. This post is meant to be a point of reference for people who perhaps aren't very experienced in these realms, but want to be. None of this is required in any sense, and I do not expect everyone to agree with everything offered here -- it is merely a convenient starting point for those who wish to learn.
This standard is by no means set in stone, but is just based on my own experience talking about science and math with others:
In my experience, it would seem that the bare minimum of mathematical ability is knowing Algebra, and how to use it in various real-life situations.
If any of you wish you increase your Math Skills, there is an absolutely wonderful free site, incredibly easy to use, to help you do that. It's called Khan Academy. You can start at the very bottom, with adding and subtracting small integers, and work all the way up to calculus and beyond. But I would say that, if you look at the Algebra section of the site and don't know what's going on, you would most definitely benefit from learning at least that much.
Another aspect of Math Literacy that is perhaps less important than Algebra is probabilistic reasoning and statistics. These are central to how science is done today -- statistical analysis play a part in nearly every experiment (if not every one altogether). Khan Academy also has a statistics course, so do try that out if you want to get into the details of statistics. There's also Bayes Theorem, which isn't taught at Khan. If you're interested in learning what Bayes' Theorem is, how to apply it, and why it's a valid/useful theorem, follow this link.
For specific topics like Physics or Biology, again, Khan Academy has some free courses that I'm sure are great. I, however, don't necessarily think that one needs to know how to calculate a Lorentz Transformation to be 'scientifically literate'. I'd imagine that it would suffice to just know some basics about chemistry, some basics about physics, maybe a bit more than basics about biology, and a bit about cosmology. More than that, though, I think that the Philosophy of Science and the History of Science are pretty relevant things to be moderately knowledgeable about. If you have anything you'd like to suggest for those two topics, please do so in the suggestion thread.
One of the most relevant topics in the philosophy of science is undoubtedly Reductionism. Read this Princeton series of articles on reductionism, or better yet, this sequence of articles about it.
Evolution is a topic that comes up quite frequently. Most people who argue that evolution is false on philosophy forums don't understand it, and furthermore, I would say that a good portion of people who argue FOR it fundamentally misunderstand it as well. Nothing in science is sacred, nothing is protected, nothing is beyond debate, including evolution -- if you think it's false, you're views are welcome to be discussed without a doubt -- but if you're going to argue it's false, I would at least suggest you first have a basic understanding of what it is you're arguing against. The same goes 10-fold for those who want to argue for it. The University of Berkeley offers this online lesson.