Depends on your skill level, attitude and style

Since I live at Lancelin and have kited here (there) for over 7 years a few tips. I generally appear when its really windy, look for the white and very old pajero on Edward island point. I may look big and scarey, but I wont bite
First DO NOT launch from the grassed area at windsurfer beach it is not safe and there are signs, leave the area to the windsurfers. So we had to make this concession, Edward island point is where you launch. If you do not have a 4wd park and walk up.
Flat WaterIf you are into flat water, probably best stay at woodies. The two flat water spots are between windsurfer beach and edward island which has rocks below the surface at varying depths depending on tides. The other option is between edward island and Back beach, this spot has the option of small waves and can be really fun.
Beginner SpotCalled north point, opposite lancelin island, clear water, no cray boats. Do not drive up the beach the sand can be tricky to the inexperienced.
WavesWell this is why I live here. Basically you have a choice of back beach, back of eddies, hole in the wall, South Passage. Generally we try to leave the main break for the windsurfers and the wave is not all that good for kiting. Back beach just what out for the odd swimmer and try and stay away from the surf clinics. Its a very big beach and room for everyone.
South passage is realy for the experienced wave rider and a locals break. My personal rules for kiting south passage are;
* Never drop In, who ever is on the inside has the wave

* Give way to those on the wave, I know going out has right of way, but it is a wave riding spot

* Try and pick up waves about were the windsurfers are gybing, while you can pick a few off on the inside, its not cool

* Ride your wave all the way in if it is busy

* Keep the jumping and tricks to a minimum, your there to wave ride, you might land on someone

* Give the a few waves away, Huey always rewards this, it is cool and may make someones day

These are my common sense, get along with everyone rules.
Other StuffYes there are jellyfish, little blue bottles they go pop when you tread on them. I have seen 1 shark in 8 years, they are well feed. There is are afew rumors, never met the people and only one is true.
Seals and dolphins often scare the crap out of ost people.
WindIt is generally windy 6 days a week, beacuse my little boat never gets used during summer. Wind tends to get a bit ify in April and May, winter starts with huge swells and storms (I average 2 kites per week from June to September) October wind starts and just gets better every month. Best time is late December to February.
Hope this helps,
Big Dasa