Consultation on the reverse proxy configuration

I am trying to configure nginx as reverse proxy and I have some
problems and doubts.

First, the settings are as follows:
Nginx 192.168.1.1
Apache 192.168.1.2

this is the original configuration http://pastebin.com/T3P6D6tV

I will assume that the settings that I’m sending is not the best or the
best.

Now, my question is this.
nginx being in a different server than Apache, I have doubts as to the
upstream and server configuration.
For example, within the server, I need to define the root path? if so,
as I define it for files that are on the other server?
and now, being defined as that what I have now, is showing no images or
css.

PROXY settings are clearly defined? I believe that understanding these
parameters that might work for a better way.

could help me fix this? I’ve been searching google possible answers,
but I find myself alone with nginx configurations found on the same
server.

thanks
I am aware of your comments (:


José Damián Garrido
Programador Web
ciber-humano