I have feeling that something like this has been asked before, but I cannot find such post, so my memory might be fooling me.
Do you think that giving here examples of usage of the most frequently used LaTeX constructions here at meta could be useful for our users? I tried to write down something for integrals here: How to show the integral symbol on this site?
If you think that this would be a good thing, what topics to you think should be covered.