I use Gimp 2 but you can use just about any paint program.
If you are using the Gimp you click on File and select New.
Pick the size of the image and click on OK.
Click on Layers at the top.Click on Add New Layer and then OK.
Open the layers dialog.I keep mine open but that is your choice.
Click on the background layer and then the trash can at the bottom.
Now you have a transparant layer.
Click on text and type whatever you want to display.
Save your image.You might want to save it as a .tga.
Hope this helps.
In answer to the question about the checkered background that is what a transparant layer looks like when you are not using it in the game.
FLA
We are all noobs at something!