As a Unix systems administrator I work with a variety of open source software including but not limited to apache, asterisk, vicidial, gnudialer, and freeswitch to name a few. When I came across squid proxy server this was an application I had no experience with so I picked up the PacktPub ebook Squid Proxy Server Beginner's Guide to help me get started.
Before I go any further I would like to explain what squid is and why to use it because I believe that many people out there have no idea what squid does. Squid is a proxy server, which in layman's terms means it is a server that acts as a middle man in between a client and a host. An example of this would be computer [A] wants to contact server [W] but the computer does not want the server to know what it's ip address is, so here we introduce the proxy. The proxy server is going to fit in between the computer and server as seen in the following graphic example.
Computer [A] ---------> Proxy Server [P] ---------> Server [W]
By doing this the server [W] will think the request is coming from the proxy server not computer [A] now there are many other uses for proxy servers but this is the basic concept behind it. Common uses for proxy servers are content filtering, client anonymity, acceleration, and reverse proxy for load balancing.
The first few chapters go over the basics of working with squid, installing, configuring, and administering the application. I found the installation instructions are very comprehensive with all the various options when compiling from source, or install from binary package on 11 different linux/bsd distributions.
The rest of the book goes into a lot of detail of configurations, examples, and anything squid could be used for which is great if you want to know the application inside out. Most people using squid will only need to take an example for what they are specifically using squid for that's why I would suggest buying the ebook so you will have a search tool.
Summary: Over all I though the book was great, it had everything squid could do and how to configure it. I was able to take a few of the examples and get them working so the examples are helpful. The last chapter is all about troubleshooting which as any IT professional knows is very helpful, it has common problems, how to solve them and it also includes a section on how to debug problems using the logs.
Easy to follow install instructions
Monitor log files and using web interface
Whole chapter on authentication including LDAP, RADIUS, NTLM
Reverse proxy (load balancer) instructions
Must be familiar with *nix before reading
Almost too much information I recommend getting the ebook so you can search for what you need
Overall I am a fan of this book if you are looking to use the squid application, just make sure you are able to navigate linux and know how to compile programs before getting this book. Also I would buy the ebook and save the paper, since the book includes so much information that the search feature will be your friend when navigating this book.