General Editing Hints

Editors are encouraged to learn the MediaWiki markup language (the same language Wikipedia uses). It's a very powerful language and relatively easy to learn.

If you choose to use the visual editor to change documents, you'll find most of what is below rather unhelpful, so feel free to skip it. Otherwise, read on.

Install wikEd
wikEd is an editor that runs inside your browser, and is specifically tailored for MediaWiki editing. It has buttons for all kinds of tasks, but I find the syntax highlighting to be the most useful feature. One of the especially handy things it will do, though, is fix chemical formulae by automatically making the numbers subscripted with the click of a button. The link describing installation procedures is below.

wikipedia:User:Cacycle/wikEd installation

Adding subscripts and superscripts
If you want to put chemical formulae in your text use the   and   tags. For example, if I wanted to write (NH4)2SO4, I would do this: (NH4)2SO4

Adding chemical equations
To insert chemical equations into your documents, such as this:

$$\mathrm{2~Na + 2~H_2O \longrightarrow 2~NaOH + H_2}$$

You need to use inline LaTeX. The above equation was generated with the following code: $$ \mathrm{ 2~Na + 2~H_2O \longrightarrow 2~NaOH + H_2 } $$

The   portion causes text to appear in a roman font. If you don't include this, all the text is italicized and less visually appealing.

The tilde ( ) is required to force a space in between the stoichiometric numbers and the compounds. You can use this anywhere to force addition of a space in an equation.

Everything else is described elsewhere is more detail, so I'll just point you to those documents:

Reed College has some good hints on using LaTeX for displaying chemical formulae and reactions (ignore all the dollar signs they throw in their code, you won't need them).

http://web.reed.edu/cis/help/LaTeX/intro.html#chem

Wikipedia (of course) has a good page describing MediaWiki's math markup language (more oriented toward math, though).

Math markup

Adding mathematical equations
This is really the same as using chemical equations. Just pay more attention to Wikipedia's page linked above, it goes into good detail.

RegEx
Some pages, particularly the recipes page, are much easier to edit with regular expressions. http://regexhero.net/ Is great for this. It lets you see what changes your RegEx code is making, with live updating. http://www.addedbytes.com/cheat-sheets/ is a great resource for cheat sheets for multiple languages, including RegEx. Again, check out wikipedia: Regular expression