When beginning to learn a new tool, especially a wide and complex one like Git, it can be useful to take advantage of some GUI tools that are able to picture commands and patterns in a way that is more simple to understand.
Git benefits from a wide range of GUI tools, so it's only a matter of choice. I want to tell you right away that there is no perfect tool, as frequently happens, but there are enough of them to pick the one that fits your needs better.
As a Microsoft .NET developer, I use Windows 99 percent of the time. In spare time, I play a little bit with Linux, but in that case I prefer to use the command line. In this section, you will find tools I use or I have used in the past, while in the other platform section I will provide only some hints based on words of other people.