Unless you began the Fireworks projects using 300 dpi at the appropriate print dimensions, you're going to have noticeable quality loss.
If the Fireworks files are completely vector, you should be able to resample in Fireworks to the appropriate resolution with any trouble. You won't have that kind of luck if you were working with bitmap images, though.
Bear in mind that FW only work sin the RGB color space, so you may see some color shifting once the files are brought into a CYMK color space. The format you export or save should be a lossless format - TIFF would be my recommendation.
Can yo be more specific about your questions about text?
Thank you much for your input.
As for text, there will be several lines of copy to each images that will be added. Does FW text feature function the same way as Photoshop and Illustrator?
Fireworks uses the same text engine as Photoshop and Illustrator, but measures font sizes in pixels, not points.