It's really quite simple because of Visual Studio. Since you're starting off, I would make a C# WinForms Application project. Using the WYSIWYG editor, I would first put in the necessary containers, go into their properties, and set them to "Dock.Fill" and adjust their settings (e.g. columns/rows) to make it the way you want it. Once you have your container done, start dropping in controls like buttons, text boxes, combo boxes, lists, and so on.
Once the UI is to your liking (remember to give them good names), you need to tie your code behind to events on the GUI. For example, if you double click a button, Visual Studio will take you to the C# code and create the event handler for when that button is clicked. If you want to add a DoubleClick event to that button, go back to the UI, select the button, look at the properties window, and click the little lightning bolt tab to switch to events. Find the Double Click event, either type a name in the box or simply double click in it and it will automatically name and generate it. When the button is double clicked, the code in that subroutine will execute.
Now for the opposite. To place data/change the UI from the code behind, it is simply [name of object].[property to modify]. For example, TextBox1.Text = "hello world" would make TextBox1 display hello world. Really simple.
