AFAIK you can't change ther resoluiton, but for the margins:
For simple adjustment of the left and right margins to one of the
three preset values, use the "Words per Line" option on the font size
page (press Aa key to the right of the spacebar on the keyboard). The
option may be named "Words per Line" but what it really does is to
alter the left and right margins.
For finer control of the margins,
the following steps require the user to access the the Amazon Kindle's
internal storage memory through a USB cable attached to a computer.
- On
your Kindle, go to the home page. NOTE: if the next steps are
completed while an ebook is open, the change will not take effect.
- Connect your Kindle to your computer with a USB cable.
- Open the folder
"system" in the root of the Kindle's internal storage memory. If
you're on a Windows machine, this might be hidden from you. Be sure to
set Folder Options to ‘Show hidden files, folders, and drives’ and
uncheck the ‘Hide unprotected system files’ option. Alternatively, try
typing in the system folder's address explicity, e.g. if the Kindle's
drive letter is H, the address would be H:\system\ Open the
"com.amazon.ebook.booklet.reader" folder.
- Open the "reader.pref" file
in a text editor. This is a plain text file with Unix line endings.
- There is a line in reader.pref that starts "HORIZONTAL_MARGIN=".
Change the number (Default=40) that follows to the desired number.
Margin-widths of 20, 15, and 10 are good starting points for
determining what you're most comfortable with. I find that 0 (zero)
puts the text too close to the bezel surrounding the display
(particularly difficult on the eyes with graphite colored bezel).
- Save
and close the file.
- Eject and disconnect the Kindle.
- Restart your
Kindle (Menu/Settings/Menu/Restart)
Your default margins when reading
books have now been changed. If you change the 'Words per Line'
preference in the Font Size dialog, you will undo the change to the
margins that you have just made.
Source: http://wiki.mobileread.com/wiki/Kindle_HowTo:_Change_Margin