How do I protect my idea?

I've got an idea for a new online business. I've done a fair bit of research, and I believe the idea is original - and valuable. What can I do to protect the idea and prevent others from copying? Will copyright protect me?

Alasdair Taylor's answer to How do I protect my idea? (1003681480)

Answer to the question: 

Confidentiality may be your best bet.

Ideas as such or not protected by copyright - certainly, ideas concerned with the operation of a business won't be protected. In some jurisdictions, such as the US, patent law can be used to protected novel business methods, but UK patent law excludes business methods from patentability. The best way to protect your idea may be to use non disclosure agreements: only disclose the idea to those who have expressly agreed not to disclose it further. In any event, given that the idea may be valuable, it would make sense to instruct a solicitor to advise.