http://hlkitwiki.wolflair.com/index....ext#references
I have this page of the wiki bookmarked:
http://hlkitwiki.wolflair.com/index.php5/Kit_Reference
Looking at that, my recently followed links are:
Other Language Statements
Language Intrinsics
Formatting with Encoded Text
Target References (within target references, I usually only need "Pick Target References", which is the link I posted at the top of this thread).
Although I haven't needed the rest in a while, you'll probably also take a look at everything else in the Scripting Language section (probably best done in order).