Sorry to bump this now it's closed however I'd like to add a bit in case this thread is referenced in future.
As mentioned above, Maltego is an interesting tool for management of information although its capability is limited by that of the operator and it takes a lot of getting used to and knowledge to use effectively.
There are plenty of open source tools which can be used for this purpose, the first thing I would recommend is to email the company who the domain is registered to. This is usually "domains by proxy", they will forward this on to the domain owner.
With the name, you can use tools such as pipl, spokeo and 192 to try to identify the individual.
Spokeo People Search | White Pages | Find People
https://pipl.com/
Search for People, Businesses and Places - 192.com
pipl and spokeo can also be used for usernames, email addresses and etc. The most useful feature of them IMO is identifying facebook / linkedin and other social media operated.
If the site is interactive and that person has a non generic username, you can try your luck googling that.
For example, hit Google and type in the "username" (and make sure to include the " as that will ensure only that exact phrase is included in the results).
Those are two of the starter ways I'd go about enumerating the owner of a website.
From there I'd progress to identifying the reverse DNS and other websites associated with that server, historic DNS records and etc however that's more in depth and for another post.
I have a very interesting book on using Google to dig information. It's in PDF format and is unclassified CIA training material. If anybody wants it, let me know (and by the same, if I'm not allowed to offer files out please let me know) and I'll stick it in my dropbox.
Also, yay first post.
