Searching the current patent literature will give you an idea of similar technologies in existence and the companies that produce them. If there are several patents in existence for related technologies, then maybe your idea is not new. Check the claims information in existing patents to make sure your idea is not infringing on those patents.
Patents also give you a large amount of technical information, with detailed descriptions and diagrams. Operational information, along with names of founders and competitors, can often be gleaned from patents.
If you are doing a patent search as preparation to filing a patent application, it is critical to consult a patent attorney and not just rely on searching the following resources.