I use a program called SnagIt (it costs...but can't remember how much) to do the editing. Extremely simple to use.
But you can probably do something very similar with a program called Gimp. It's a 100% free photo editing program. It might not be as simple to use as SnagIt, but I'm sure you can figure it out.
To find both programs just go to Google and type in their names. Should be the first result that comes up for each.