Ceramic pizza stone - How to use?

Hello,

I bought a ceramic pizza stone at Home Sense and the inadequate instructions were written in french.

Lucky I know a little french and was able to deduce the basics of care and handling.  But I still don't know how best to use this thing.  I have a gas oven with option for convection heat.  When I bake my pizza on the ceramic round, do I place the ceramic round on the very bottom of the oven, or on the lowest rung?  And would I ever use convection heat?

Any tips would be appreciated, thank you!

Mira