This guide will be for people who have not heard of or have not practiced this before. This requires nothing aside from your browser and a few know how's of google.
Firstly, what can doxing be useful for? It can help you find out information on the employee who is always "sick" when that new movie/game comes out or the one who is always trash talking in that shoot-em up game Call Of Duty.
As you can see it can be used for varied reasons, some serious and some not so serious.
Google has a few tricks i will be going over to help you search for things, things that don't have to include doxing but to help you find some answer you need faster then the way you do it now.
Google search operators:
1.)Don't quote me on it: Putting a phrase or a user name for example inside quotes will yield you only the exact phrase you typed inside those quotes. This is useful for if you're looking for something specific. "Nevada hotels"
2.)A dash to the past: A dash (-) prefixed to a word will leave that word out of the search results you receive. For example, type in face to your browser and the first result will probably be facebook. now after the word face type "face -book" and now you will no longer receive anything with book. This is useful for narrowing search results. "Nevada hotels -cheap"
3.)Two dots please: To see numbers within a range you can for example search for hotels within a price range of 60-100 dollars per night, or searching for a specific price you can just use the "$" operator before the preferred price. "Nevada hotels $60..$100"
For more on google search operators just google for them as there is plenty to use.
A successful dox will be when you have the following:
Information on there family/friends
There can be more things you may decide to grab, but those you will have to decide as a successful dox can mean many things to the individual wanting to do it.
The plot:Guy boots you off line for "being a douche", you think "oh, I will dox and report him!" This is just a simple plot.
To go about the Dox when you are starting, say you have a user name. You google that user name with quotes, you find a few results of that user name and one of them is a link to an on line game. Now you can't just assume that is the guy/girl you are looking for as two, three, or even four people can be using the same user name across sites.
Look into it anyway, note the information you find (anything from an email to a D.O.B) and were you found it from in a file. You then click on a link that leads to google+ and you find some information, be it a video of him and his buddies recording themselves doing a 24H stream both picturing there faces and XBOX/PSN id's.
SURPRISE!!! The I.D matches the I.D of the guy who booted you off line, you now know what him and his buddies look like which will just pile more useful things onto your search.
Now it will not be that simple all the time. You will probably have to go through google searches, on line profiles, people searches and maybe even some social engineering can yield some valuable information. Remember to record every piece of information you may get because it may prove useful later on.
For example you may not find information on a persons profile directly but they may have a friend/parent who has just a little information posted on your target to help your search.
Some sites to help you on your way: 411.com pipl.com and any social media is a good place to start.
This is the end of the guide, it may be short but it may have introduced a few to something new and will go nicely with the "Many Lookup Engines" post from UCP GUY.