Yeah Tognar is a good place to get stuff. Search for Reliable Racing too, they're prices are allright on some things. First, unless you are a racer, don't bother buying one of thos wax irons, they're a ripoff, just see if you can find some regular electric iron without holes. It works just as well if you are willing to tweak it every now and then so it doesn't smoke the wax. Other than that, the essentials are a couple Ptex sticks, a plastic scaper, a metal scraper, a gummi stone or some ceramic stone, and a file and some sort of guide for it. There are a lot of companies out there that make a base and edge guide in one little plastic thinger. Also, I think Tognar has a tutorial on tuning if I remember correctly.
The key is if its just park skis, don't overdo the tuning, they just get fucked up right away again on rails anyway. Mainly I just keep my edges deburred so nothing catches. Rarely do I ever actually full out edge my park skis, it's fairly pointless. Waxing is key tho for speed in the park, don't skimp there.
'180 net grab = NOT a new trick!'
Have you ever seen a little kid slide back down the inrun of a kicker without going over? This is why parents shouldn't dump their kids off anywhere near the park...