Hot waxing is by far the most effective method.
Better still it to put your skis close to a woodstove or pelletstove for a few hours before scraping the wax off. This has the same effect as using a "hotbox" so that more wax is absorbed into the base. Aim for 120°F and try not to exceed 130°F. The wax may turn enter a semi-liquid state, but this is okay. Hotboxing makes the bases even harder and faster than hot waxing alone. Also you won't need to wax quite as often. The difference is certainly noticeable.
The wax I use can be found here: http://www.tognar.com/swix-universal-wax-cold-900g/
I also use the "warm" stuff here: http://www.tognar.com/swix-universal-wax-900g/
Unless your looking to be 1 second faster (if that) on a 30 second race course, universal wax is plenty adequate, and cheaper than temperature-specific wax. I would recommend the cold variety for the east coast if your planning on getting one variety. Its harder than the "warm" stuff and will last longer.
900g = Five 180g bars (standard size)
A single bar might last you 12 waxes? I guestimating.
Wax every other day if you have a sintered base (ideally), and everyday if you have an extruded base (ideally).
Waxing makes you faster. More importantly it makes skiing easier and protects the bases of your skis.
Life's a mountain, not a beach.