I am 6 months into my Arduino Uno work and I would like a step by step way to find and download a "library". I work using WINDOWS and WORD and although I was eventually successful in getting a 7 segment display library to download and work, I must say I could not do it again since the path I followed was far from clear due to my lack of understanding about basic computer stores etc. I have enjoyed my work with the Uno but I have been very disappointed at lots of "help" offered on other sites since they assume I know far too much. It is a skill to be able to communicate with we lesser people so I am really hoping a step by step guide is possible. Thanks
Start with the newest Arduino IDE. At this moment that is version 1.8.1.
Try to find the Library Manager. Via the menu: Sketch / Library...
In the Library Manager there is a input field in the upper-right corner where you can search for libraries.
If you can not find the library, then the next step is to download a zip file from Github. There is probably a green button "Clone or Download" on the right side with that project on Github. Use it to download that library and store it. Do not unzip it. In the Arduino IDE in the menu via: Sketch / Library... there is a option to install a .ZIP file. Use that to install the library from Github.
Your projects are probably at: Documents / Arduino
There is also a folder: Documents / Arduino / libraries
That is where the installed libraries will end up. That means you can also add libraries to that folder. Each library in its own sub-folder.