Personally I wouldn't because its really only serving as a sort of shovel, dusted with semolina/flour, to get the pizza into the oven. Its not a chopping board. But maybe others will say differently.
It isn't really necessary, but it doesn't hurt. It's not like you'll end up with an oily peel, it just helps keep it from drying out so much. A lot of pizza peels are really cheap and poorly constructed, and won't last all that long no matter what you do. 
I switched from a wooden peel to a metal one several years ago and, though it's not "traditional," (like I give a toss), I much prefer it.
I switched from a wooden peel to a metal one several years ago and, though it's not "traditional," (like I give a toss), I much prefer it.
CraigC
Guru
No. I use coarse corn meal on the peel (aluminum) to help slide the pie onto the stone. You don't notice the corn meal on the finished pie.
Yeah corn meal will work as will fine semolina. I thought pocofan was talking about oiling it to preserve the wood rather than to lubricate it for the pizza.
CraigC
Guru
That was what I thought as well. Never crossed my mind to use oil for a lubricant.