Make blog on a subdomain I need some help figuring this out. I have a main site mysite.com on Drupal 7. I want to build a blog for it and want for people to access it using blog.mysite.com. So basically it's the same site (so I can manage content from the same place), just on different URLs.

NOTE*: Individual posts page should show the URL like so: blog.mysite.com/my-post

I was wondering if this can be done using a View under the path name mysite.com/blog and mask the URL somehow to show blog.mysite.com instead. I am using nginx as a webserver.
Sounds like you'll need to use the Domain Access module to get this right. This module allows you to run as many affiliated sites as you need from one single Drupal installation, sharing the same database. 

I'm using it for another site at the moment, and it works really well.