1. Hacking tools described and/or available for download:

http://www.hacked.net/exp/nasa/030597/

The members on this site are obviously quite resentful when it comes to hacking laws. "Our mission is to continue where our colleagues the ILF left off. During the next month, we the members of H4G1S, will be launching an attack on corporate America. All who profit from the misuse of the internet will fall victim to our upcoming reign of digital terrorism. Our privileged and highly skilled members will stop at nothing until our presence is felt nationwide. Even your most sophisticated firewalls are useless. We will demonstrate this in the upcoming weeks. " THis goes to show that these hackers really intend to do evil with their knowledge, stopping at nothing.

http://www.hacking.teleactivities.net/

This site has methods for cracking lots of system, providing tips, tools and tutorials.

2. How do you suppose these techniques might be prevented?

Developers & programmers will just have to continually improve on their products etc in order to stop hackers from using these techniques. Unfortunately, hackers will always find a new way around everything so regular updates of programs, etc. should be obtained and installed on your system. Be sure to update your anti-virus program on a regular basis.

3. Is it good that such detailed instructions are so freely available on the Internet?

Well, I'd say it's a good thing. It makes it so much easier for developers and programmers to do some "research" to see how they have to improve their programs and websites to prevent possible security leaks.

4. Should network administrators monitor hacker site? Why or why not?

Yes, they should. This will help them stay up to date with what hackers have found out. Some hacking sites even list sites and programs that they have hacked recently and telling people how they did it. All sites should be monitored.

IBM has a very informative web page about password cracking
The techniques included Spoofing, Smurfing and DoS

A. Methods:
Dumpster Diving: Attackers go through rubbish bins to find company documents with password on
Dictionary Attack: A Dictionary file is loaded into a cracking application to find the right password.
Hybrid Attack: By adding numbers and/or symbols to the File name a password could be discovered.
Brute Force Attack: This is a very time consuming and complex process. It can take up to a week to crack the password.

Tools:
LOphtCrack also known as LC4: This tool takes Windows NT/2000 passwords and changes them into plain text. Bu using Alphanumeric combinations it can solve the password.
Protocal Analyzer: Also known as "Network Sniffer"

B. Prevention:
Strict Security Policies should be adhered to. Networks should involve Security Professionals, end users and management representatives to come up with solutions to their security needs.

C. Yes, detailed hacking information is freely available on the net but on the flip side of the coin so is Anti-Hacking information and software with regular free updates also available.

D. Yes, network administrators should monitor Hacker sites to stay one step ahead of them. All this free information could be beneficial for administrators to enable them to update their security solutions.