Donald, the short and sweet way to mount your router is a Rousseau mounting plate. You can purchase a centering kit for like $3, and a template kit that includes a special guide bushing for getting a perfect fit every time. Don't take my word for it on this plate. Norm used this plate for 10 years on the NYW. When Rockler started sponsoring the show he "upgraded" with Rockler supplied goodies. I have installed 4 of these plates so far with more to come when the weather warms up.
"Living in the D" (this means Detroit!)
"It's fine to disagree with other members as long as you respect their opinions"