Add logo to print on Invoice and packing slip

[RixStix]

1. Flag that appears in admin on product pages

Flag in admin /includes/languages/english/images/icon.gif

Find a GIF icon of whatever flag you want to use (google can be your friend), name it icon.gif and replace the stock flag with your new flag.

Changing the filename of the actual logo and editing the files will only be troublesome when you start a future upgrade. At that time, you might realize that it was not worth the hassle of doing those namechanges.

Are you still having problems with the flag icons in admin? Did providing the location of the flag icon not help? Replacing a file is a pretty basic operation.