What Iain said… We all had to start somewhere, with no official documentation provided by Waze - everything we’ve learned about how WME ticks behind the scenes, whether it’s something as simple as figuring out how it renders a certain bit of the editor UI, right through to how it interacts with the backend servers to load and save data, has been learned through hours of poring over the debug console, looking at what server calls are made or received when a certain action occurs, tracing through the somewhat less than readable WME code to find references to certain objects, or just by the age old method of trial and error. The debug console, and particularly its ability to run javascript directly in the current webpage simply by typing it into the console and seeing what happens, will become your best friend and worst enemy…
Just when you think you’ve understood what’s going on, WME will throw you a curve ball and remind you that it ain’t all that easy to get to grips with, but if you continue to persevere and crack the problem at hand, you’ll be rewarded with a feeling of immense satisfaction. And, if the reason for writing a script is to help other editors as well as yourself, you’ll also start to get that warm glow you get knowing your work is making life a little bit easier for others too.
One other thing I’ll add for future reference (i.e. once you’ve found yourself well and truly hooked on script writing) is that, if possible, you shouldn’t restrict yourself to using just one browser for development. As a Windows user, my scripting environment consists of Firefox+Greasemonkey+Firebug, and Chrome. I do pretty much all of my primary development work in Firefox, partly because I prefer the way the Firebug debug console behaves when poking around in the page source code or DOM tree and also when running bits of code directly from the console, and partly because, once I’ve installed the first version of a script, I can then edit its source code directly out of the Firefox profile folder and bypass the usual script installation process each time I want to try out the latest changes I’ve made. It might not sound like a big deal, but if you’re spending a few hours working on a script and going through a period of short change/test cycles, the few seconds you save each time by not having to “officially” install the new version each time can quickly add up.
However, whilst I prefer the Firefox environment for editing, delving into the innards of WME, and some testing, I much prefer Chrome for general testing - its debug console provides better runtime error messages, showing things that Firebug is quite happy to ignore but which really need to be fixed in order to make your script run well, or indeed at all…
But to get started, just take things nice and easy. Look at some of the smaller scripts that are already out there so you get a feel for how things behave, spend some time playing around in the console - remember that if it all goes horribly wrong, a simple browser refresh/reload will get you back to where you started - and don’t be afraid to ask for help.