In addition to these links there is also the mIRC help file. I have found this to be among th best scripting resources there is. It's only downfall is that the examples given are intended for scripters with at least some experience or general knowledge of how programming/scripting languages operate. This is where the tutorial websites come in as there is often examples of commonly used scripts with a plain English description of what it does.
Warning: Don't just copy/paste code you are given by others without making absolutely sure of what it does. This is not to scare you but to inform you that mIRC scripting does have some powerful elements that used wrongly can be destructive and in some cases irreversible. Reading a universally trusted website like the ones given is much better than being given code on IRC.
All the best.
