I'm working on a book about handheld router techniques and am also developing some specialist sections on both trammel and template routing. I've posted some images at www.tutorwood.com, so you can see how things are developing. If you have experience with template and trammel routing or you just want to learn more about using routers I'd love to hear from you.
Generally arcs, and circles are not routered freehand but with either a template or an aid such as a trammel.
It may look complicated but it does get easier with practise. Please post some photos of the work you're doing and please don't hesitate to ask any questions.