using ImageMagick through SSH to resize directories full of jpgs

[piston]

I dont know if this is the right forum for this - dont shoot me.

I'm trying to find the right way to resize all of the photos in a certain directory directly on my server. I have this code so far but I get some errors:

find . -iname "*.jpg" | xargs -l -i convert -resize 640x480 {}{}

Does anyone know how to go about doing this? I don't know much about it.