depends on what your doing, i have made a thread on types of waxes and how to apply them but it is a little to complex for the average newschooler.
if you are a park skier, just use some all temp wax, i found green toko wax works best.
on skis that are used for real skiing you want to layer your waxes, I start with green toko, and i "hot scrape" the skis. then i put a fluro wax on, either a low or high fluro all swix.
something to note is that swix owns toko, so not really sure what the differences in their waxes are.