It is essential to conduct a search to make sure that you are the first person with the idea. Start by going to the type of store that would eventually offer your invention for sale. For example, if your idea is an office product, go to office supply stores and make sure that you do not find your invention already being offered. Also, check specialty catalogs that might be likely to carry an invention such as yours. If you do not find it at the kind of store that carries similar items or in a catalog, then it is time to do a patent search.

You can conduct a fairly thorough search online by going to www.uspto.gov. Enter every key word that you can think of to describe your invention. It is also very important to do a "classification" search. Many times you will come across inventions listed in the same classification as yours that you might have missed doing only a key word search.

It is also very important to search all possible years. You can do that search without cost also. Or, if you wish, you can hire the search to be done by one of the firms that specialize in this service. Several such firms are located in the Washington, DC area. It is possible to do a good patent search yourself. Your local inventors association or patent attorneys can refer you to patent search firms if you choose to go that route.