ALWAYS thoroughly check all tools for damage and flaws before using.
ALWAYS wear safety glasses and ear protection when using power tools.
ALWAYS thoroughly read the owners manual and manufacturer's instructions before working with tools.
ALWAYS be sure that at least 75% of the shank is securely inserted into the collet of the router.
ALWAYS use template guide collars when possible to absorb lateral forces that can deflect the bit.
ALWAYS watch for special safety warnings that apply to specific bit profiles. Remember that certain bits are for use in certain machines and check to make sure you have the correct bit for that machine.
ALWAYS use a router table and fence when possible.
ALWAYS use a fence when working on the router table.
ALWAYS reduce the router speed when working with larger diameter bits, see the chart below for suggested routing speeds. If your router doesn't have a built-in speed control, a number of speed controls are commercially available.
ALWAYS keep your fence adjusted so there is some clearanace between the router bit's bearing guide and the workpiece.
ALWAYS take care to remove large quantities of stock (cross section>3/8" (10mm)) in more than one cut.
ALWAYS Keep your tools sharpened, clean and stored in a safe place to avoid breakage and accidents and to extend the life of your bits and blades.
NEVER use dull or defective router bits.
NEVER force the shank entirely into the collet (bottoming out). Leave about a 1/8" space between the end of the bit's shank and the bottom of the collet.
NEVER force the cut or overload the router.
  courtesy of CMTUSA