I am trying to find out which is the best flour to use in America that would be the same as English Plain and Self Raising flours.
Thanks Gina

Plain flour is all-purpose flour in the USA.

Self-rising flour should be available in stores, but you can make your own as well...
1 C all-purpose flour + 1 ½ teaspoons baking powder + ½ teaspoon salt

This is a really good website for substitutions.
http://www.foodsubs.com/Flour.html