There are many ski tuning guides, books and videos available - I have read and seen most of them :).
As a ski racing parent, here's all you need for a
U10 U12-U14 U16-U18
Or, per topic, here's what we have:
Base Edges Waxing Routine
Here's the external articles I consider most interesting:
Other ski tuning articles worth reading as you get serious about it:
Razie's guides, distilled from all I know:
If you haven't tuned out at this point, there's a lot of very interesting videos about ski tuning. You can pick up small tips and ideas from each, here's my favorites: