1. To see the “bin” folder in Visual Studio .NET you will have to select the “Show All Files” option in the Solution Explorer. Drag the appropriate DLL (RichTextBox.dll for example) and the XML file into the bin folder and it will automatically add a reference to the assembly for you. Alternatively you may add the control to the Web Form's Toolbox (3. below) in which case the drop and drag of the control onto your .aspx page creates the appropriate DLL reference.
2. Drag the Images folder into the root of your web application.
3. Select the Visual Studio Web Forms Toolbox then Right-click and select "Customize Toolbox", click ".NET Framework Components", click "Browse", and locate the appropriate .dll Click Open, and click OK. Your Toolbox will now display a new Toolbox icon which you can drag onto the page and then configure the properties. Installing it in Visual Studio .NET also means the Control is rendered in the Design View. You only need to add the Control to the Toolbox once and it will display for all Projects going forward.

If you find that the Toolbox icon is greyed and inaccessible, right-click on the Toolbox again and select Customize, and then Reset Toolbox. Very occasionally the icon fails to appear, but this seems to kick Visual Studio into action.