Does everyone just play around with it until they know how to use all its features?

Sort of... Most of the stuff available through the menus are pretty self-explanatory. What I haven't played with is the IR-translations or tweaking the VolAdjust settings(no need). Just noted that there are links to explanations for those two...
What commands that are available for ftp is listed if you send a 'HELP' and/or 'SITE HELP' command...

HiJack has been under very rapid development, features has come and gone (SITE EXEC for instance) or changed behaviour slightly - documentation hasn't really been able to keep up. I think there was someone who volontered to start on a tutorial (Mark was asking for him recently - or was it a general cry for a tutorial writer?) but it's not here yet.

If anything has you stumped and you can't find it on Marks site or in the FAQ, don't hesitate to ask here - generally you'll have an answer in no time...

/Michael