may as well avoid paint for modern editing, as it is beaten by almost all free open source programs;it doesnt even allow some very basic stuff.
woud extremely recommend GIMP [GNU image manipulation program,see its nothing dirty]-
http://www.gimp.org/ it is completely free and can be described as a entry level or home users photoshop.
it can be made an
even better program by modding it with the GIMP painter mod-
http://www.davidrevoy.com/?article31/installing-gimp-painter-on-windows and GIMP paint studio-
http://code.google.com/p/gps-gimp-paint-studio/ -both of these are completely free as well.
pinta is worth an install to-its like the modern version of paint but with more functions;
http://pinta-project.com/ its just quicker to use than programs like GIMP if are only doing basic stuff like changing to jpeg or cropping.
am going out right now and cant add anymore at the mo,but if are on the art site deviantart,go to forum search and search 'free paint programs', theres loads that are helpful.