I encourage many of my inventors to do their own patent searches, especially when they are developing new ideas. There is nobody more qualified to perform a search than the inventor who knows their idea and can benefit from seeing other people’s versions of their idea.
Note: many companies have a policy that prohibits employees from performing a patent search for work-related inventions. This is because there is a quirk in US law that assesses triple damages if a company knowingly infringes another person’s patent. This provision has the downside that no large company will use the patent database for its intended purpose, which is to disclose trade secrets so that everybody can improve on them.
Here is a link to a search tutorial:
The USPTO course shows how to use the classification system as a key element of the search process.
I recommend trying Patent Classifier, which is an automated tool that helps you perform classification-based searches. An introduction on how to use Patent Classifier is here. It follows the same searching principles of the two tutorials above, but in an easy-to-use system.
A word of caution: In order to do a good patent search, you will need to be objective and dispassionate. Many inventors, myself included, do not want to hear the bad news that someone else came up with their idea before them. This is one reason why I will often hire a patent searcher whose sole objective is to find prior art.
A second word of caution: The USPTO has recently scrapped the old classifications system and gone to an new classification system. The tutorials may describe the old system, but the same principles/techniques apply to the new CPC system.
As a result of your search, you will find several patents that are ‘close’ to your invention. Make sure you keep a record of these patents, as you will be required to submit them to the Patent Office when you file your patent.