A couple of ways to get it done...
You can use a button, but set its FlatStyle property to Flat and BorderWidth property to 0. Add an image to the button and you're good to go.
Another way is to dock a TableLayoutPanel in the form and add PictureBox controls to it. Set the Image property of each PictureBox to the image of your choice, and handle the Click event for each one the same as handling a button's Click event.
You can set the Padding property of the TableLayoutPanel to put some space between the PictureBox controls, and its CellBorder property to give it a nice look. Check out
this[
^] article to see flat buttons used within a TableLayoutPanel in the screen capture image.
You can of course draw images directly onto the client area and handle the MouseMove and MouseDown events, but that's a bit more involved to code and probably not as fast as the methods described above.
Hope this was helpful.