I have been translating most of the .ini files and placed then in the sv-SE directory under adminitsrator and the regular language files accordingly to your instructions under the FAQ directory.
I don't get everything translated in the backend anyway...well well not a gigantic problem but some things are annoying and don't look professional.
Here's a front end example when you have done check in time and check out time for a room reservation you get the pop-up window with three options (see image attached) the swedish letters å ä ö are formatted like this å ä ö but in the other places like backen you have to use this format in order for those letters to appear right...
How xan I change these settings?

Another thing is this how the object displays (Where do i fill in the Features infomration??)

Hello, buttons label are HTML saved with PHP methods htmlspecialchars or htmlentities.
I'm very surprised that they corrupt Swedish.

Try fix it in following way:

open components/com_booking/site/views/reservation/tmpl/form_add.php

there are rows on the beginning:

$titleCheckout = $this->escape(JText::_('Save checkout'));
$titleContinue = $this->escape(JText::_('Save continue'));
$titleStorno = $this->escape(JText::_('Back'));

improve they:

$titleCheckout = JText::_('Save checkout');
$titleContinue = JText::_('Save continue');
$titleStorno = JText::_('Back');

I don't know what title Features is. Booking doesn't generate it.

Thanks this did it on that dialog pop-up but when you go for the option Save and go to checkout then another translation errors occur (see picture):

I forgot to add that the Supplements text is neither translated.
Do I have to change some php file for those translations as well?

Hello if some text isn't in .ini file you can add it in your own.

E.G.

TERMS OF PRIVACY="Villkor Sekretess"

Text on the left side has to be in upper letters.
It's possible to not use & in texts?

Hello!

Ok I will try to add this.

ä = ä in swedish alphabet
å = å
ö = ö

I don't know if I can type in just the å, ä and ö letters but it seems like if I do then the output in frontend gets corrupt like some strange sign between the usual letters.