Stower-

I work with my images in Photoshop and there its quite easy to convert from RGB images to CMYK with a drop down menu Image to Mode.

When I'm working with images, editing them or adding text, each operation frequently happens on a new layer and I then opt to "flatten" all the layers.

I then "place" the images into my layout software which is In-Design, which I've learned to work with. One of its assets is at the end of your project it will "package" all your JPG images and fonts with your layout so that the printer will be absolutely delighted.

However, I also send a PDF of each page of the image just in case none of the above works at the printer's end.

It's also useful to print out your own proof copy of what you think the document should look like (assuming you have a decent printer), and send that to the printer.

The frustrating problem is that layout software is always being upgraded and your printer may have a newer version, or an older version of what you are using. So ask the printer what they have before you submit the job for printing.

Cheerily,
Charley Noble