I have a wordpress pre-made site which were developed on my localmachine, and i uploaded it too a vps running on debian6, using nginx, mysql, php. Following this guide:

1) Create an unprivilaged user, this could be say 'karl' or whatever, and make them belong to the www-data group. So that if I were to login as karl and create a web root in say /home/karl/www/ , all the files will be owned by karl:www-data

2) Set up nginx as the user www-data in nginx.conf

3) Set up PHP-FPM to run as www-data

4) Place your files in /home/karl/www/[domain name maybe]/public_html/, upload as 'karl' so you don't have to chown everything again.

when i type ls -l inside public_html/ it shows that all the files inside are owned by karl:karl. But the public_html directory is owned by karl:www-data.

I chmod 0755 the folder wp-content but i still get the error:

ERROR: Path ../wp-content/connection_images does not seem to be writeable.

I know i shouldn't set it too 777 due to security reason, how should i set it too proper permission? and what should i set also to allow my users to upload,write posts,edit articles?

Sorry for my english by the way.