To use the NuGet package manager dialog within Visual Studio, you will need to open an existing project.  Once the project is open, select the Tools option on the main toolbar, then select NuGet Package Manager, and finally select Manage NuGet Packages for Solution. This brings up the NuGet package manager dialog. On the left-hand side of the dialog, click on Browse. The NuGet dialog will then query the NuGet website and show a list of available packages. At the top left of the screen is a search box. Click within the search box, and type jquery to show all packages available within NuGet for jQuery, as shown in the following screenshot:

Each package will have an Install button highlighted when you select the package in the search results panel. When a package is selected, the right-hand pane will show more details about the NuGet package in question. Note that the project details panel also shows the version of the package that you are about to install. Clicking on the Install button will download relevant files, as well as any dependencies, and include them automatically within your project.