settings

Where is the setting to turn attachments off/on?

Administer > Content management > blog entry (or other content type) 

Workflow settings > Attachments > change to enabled/disabled > [Save content type]

(The default is enabled.)

Poormanscron settings are found at the very bottom of the site information page. (Administer > Site configuration > Site information)

What are drupal's recommended file permissions?

According to the drupal documentation:

File Permissions in a Nutshell

/default on 755
/default/files including all subfolders and files on 744 (or 755)
/default/themes including all subfolders and files on 755
/default/modules including all subfolders and files on 755
/default/settings.php and /default/default.settings.php on 444