For sharp text Use 100% black for all black text. Avoid black color builds and never use registration black.
Need a rich black that has more depth that 100% black for your designs? Use 60% cyan, 40% magenta, 40% yellow and 100% black. Avoid registration black (100% cyan, 100% magenta, 100% yellow, 100% black) it will created additional cost and make your colors muddy.
As a guide, any text that is 12 point or smaller should never be designed to print in more than one ink color to ensure a crisp clean final product; it is best to use black or a spot color to ensure a crisp clean final product.
All images need to be a minimum of 300 dpi. Web graphics should not be used, they are RGB and usually 72 dpi and not ment for printing.
When possible use vector images rather than raster images. Vector graphics are based on mathematical formulas. Because vector graphics are composed of true geometric primitives, they are best used to represent more structured images, like line art graphics with flat, uniform colors.