I have a questions! I have created a file 300 dpi cmyk.

I now want to send it to the printhouse.
Do I need to change something in the color setting of adobe photoshop?
I use webgraphics default and with cmyk it reads US Web coated (swop)v2).

Is this correct or do I need to change it to something else. And if so, can I do it now once I am finished or do I need to start all over again!?
Thanks in advance,