Don't Talk About It
If the invention has been described in a printed publication anywhere in the world, or if it has been in public use or on sale in the United States before the date that the applicant made his/her invention, a patent cannot be obtained. If the invention has been described in a printed publication anywhere, or has been in public use or on sale in this country more than one year before the date on which an application for patent is filed in this country, a patent cannot be obtained. In this connection it is immaterial when the invention was made, or whether the printed publication or public use was by the inventor himself/herself or by someone else. If the inventor describes the invention in a printed publication or uses the invention publicly, or places it on sale, he/she must apply for a patent before one year has gone by, otherwise any right to a patent will be lost.The Main Reason Why
You have to do (or hire someone else to do) a patent search before investing in the cost of patenting . Even if you hire someone else to do the patent search for you and that is highly recommended for beginners - do a preliminary search yourself and bring that research to the intellectual property attorney or agent that you hire . Doing so will save you money, plus provide the other benefits mentioned above.Utility patents
Utility patents are for either a: process, machine, article of manufacture, composition of matter or an improvement of any of the above. Patent protection is also available for (1) ornamental design of an article of manufacture (design patent) or (2) asexually reproduced plant varieties by design and plant patents (plant patent).What cannot be patented?
Laws of nature, Physical phenomena, Abstract ideas, Inventions which are considered not useful or possible by the USPTO for example perpetual motion machines; or offensive to public morality.How to Conduct a Patent Search
To get a basic understanding of patent searches read Searching For Students and in particular read Searching Using Key Words . It was written for students; however, if you can look past the cute language it will quickly get you reading and searching patents online within minutes. It will not be enough to do a diligent (complete) search for prior art by only using the Internet. For that you would need to understand the patent classification system and be prepared to do days or even weeks of research.