Black & white line art: The imagesetter is capable of printing more than 2540 dots per inch, so your scanner should be set to: black & white (lineart) as high a dpi as possible. We shoot for 600-1000 dpi at the final size intended.
(DO NOT use grayscale to scan your black & white lineart. You will end up with a big file on disk at 1000dpi !) if you enlarge your 1000 dpi image in Pagemaker to 200% of original, your final image is now 500dpi - and vice-versa. Only scan up to the OPTICAL resolution of your scanner. It may be advertised as a 4,000dpi machine, but the optics only scan at typically 600 - 1000dpi, and the higher resolution is "faked" by software. Only "optical resolution" counts in the real world.

We cannot color individual parts of your scans. If you want part of a logo colored, you should rebuild the object in a drawing program, or obtain the original from the artist/client. It will usually be an Adobe Illustrator EPS file or a CorelDraw file, which is easily manipulated. Artist must provide fonts, or convert all fonts to outlines.
Your print provider does not posses all of your fonts.

Grayscale & color halftones: scan at double the line screen you intend to use at final size. At 100% size at 133 linescreen - you scan at 266 dpi. so, if you intend to enlarge your photo to 200%, you have doubled the size of the photo, and you need to double the resolution of the scan. 266dpi x 2 = 532dpi most people just stick to 300 dpi to avoid thinking. mistake : too high of a resolution is a waste of your disk space and our time. you CANNOT see the difference.