Funny, I also wanted to do this same config… Just finished a few days ago. Here’s what I learned:
Mikrotik:
/ip proxy
set always-from-cache=no cache-administrator="" cache-hit-dscp=4 \
cache-on-disk=no enabled=yes max-cache-size=none max-client-connections=\
600 max-fresh-time=3d max-server-connections=600 parent-proxy=10.1.0.100 \
parent-proxy-port=3128 port=8080 serialize-connections=no src-address=\
0.0.0.0
/ip firewall nat
add action=accept chain=dstnat comment="" disabled=no dst-address=\
!10.1.0.100 protocol=tcp src-address=10.1.0.100
add action=redirect chain=dstnat comment="" disabled=no dst-port=80 \
protocol=tcp to-ports=8080
10.1.0.100 is the ip of my Squid Server, change it for your needs.
Linux:
I used Debian/Ubuntu ( http://www.debian.org or http://www.ubuntu.com ) and Webmin to help me configure Squid ( http://www.webmin.com )
Hope this helps, still learning Mikrotik and Linux myself.