Here are all the articles about ski waxing :
If that's not enough for you, then here's the most interesting stuff I found on the net: Ski Tuning Guides.
Use fiberlene between the iron and the wax/ski. Get a small strip to cover the base of the iron and it will be very useful especially when waxing hard/cold waxes with high temperatures, as it helps protect the base from over-heating.
Here's some more interesting articles and discussions from all over the web: