I've been searching for an easy-to-understand tutorial on fetching web pages using sockets in Python, but haven't been able to find a really newbie-friendly guide.

Could someone point me in the right direction?

Yes. First you need to learn the Basic HTTP protocol. Here(http://www.jmarshall.com/easy/http/) is excellent tutorial for the same. It teaches the protocol by using telnet. Then you should learn about sockets (http://docs.python.org/library/socket.html). Also, read the Beej's Network Programming Tutorial (http://beej.us/guide/bgnet/) it would be helpful, although it is intended for C programmers.
Next use socket's send and receive functions to interact with the web server as you would do with a telnet program.

But I strongly don't recommend you to do all this fuss. UrlLib along with urlLib2 is very powerful library. It can do many things. Use it.