Since I’m being lazy this post is mostly for me. Here’s a good starting place:
Egghelp.org
After you’ve downloaded the tar.gz file, uploaded it to your server, and pretty much gone to ./configure, then come back here.

If you can go to ./configure and everything runs peachy, you’re a better system setup guy than I am. Otherwise Eggdrop requires TCL to be installed and compiled (you should get some sort of compiler error saying it can’t create executables if not installed).

apt-get install gcc
apt-get install tcl8.4
apt-get install tcl8.4-dev

That’s it. Go and run that ./configure again.

Unless you’re on Ubuntu 14.04…
./configure --with-tclinc=/usr/include/tcl8.6/tcl.h --with-tcllib=/usr/lib/x86_64-linux-gnu/libtcl8.6.so

I had just finished installing Ubuntu 7.10 on a virtual machine. This virtual machine had no active connection to the internet (which is why this actually happened).

After install, I tried to run the software update service. It said that there were no updates to install. I tried to apt-get install ssh and that failed too. So I tried apt-get update. No updates. Hmmm.

It turns out that if there is no active connection, Ubuntu will comment out all the sources for software in the sources.list file. You can find it here:
cd /etc/apt
nano sources.list
uncomment some of the repositories and save the file
apt-get update