sharpening for print.

I've been trying to solve this problem for a while.

When I prepare an image for online viewing..I sharpen twice. Once before resizing (for web use) and once after... I'm usually very happy with the results.

When I sharpen an image to send to my photo lab, I sharpen only once. I don't resize my images for my photo lab because they strongly suggest that customers leave files in their "native resolution" and let their software resize as needed. In short, I don't apply the second round of sharpening.

Do I need to resize every image to the exact print size and then apply a second round of sharpening?

I resize my images myself, then sharpen once for print. The 'master' file remains unsharpened.
This leaves me in control of the output, not the photo lab.
Have you been pleased with the results from your lab so far? If so, why mess with a good thing?

For prints, I use PK Sharpener, and have been very pleased. It consists of several rounds of sharpening, starting with a light round of capture sharpening, then creative sharpening, then output sharpening, which is done at output size. When I have an outside lab print for me, I supply the file, sharpened, at output size to them.