== proxy for apt ==

edit
/etc/apt/apt.conf

or
$ sudo vi /etc/apt/apt.conf.d/60proxy
Acquire::http::Proxy “http://x.x.x.x:port”;

Don’t miss the trailing “;”.

The proxy can be in pac form:
“http://x.x.x.x:port/accelerated.pac”

URL:
http://en.wikipedia.org/wiki/Proxy_auto-config

== proxy for wget ==

wget -e http_proxy=http://x.x.x.x:port -c -m -np -k URL