In addition to having a bigger information base, Google also ranks the search "hits" by how often they are actually accessed in the course of searches rather than by the frequency of keywords in their titles, texts, and/or meta indicators (any of which can easily be jimmied). By ranking by the frequency of access, Google gives you the benefit of the experience of the community of users that search for the same things you seek. Archeologists, for example, already have an inkling of which Internet sites might have what they want, so they will link to those sites most often and move their chosen sites up in the rankings. (Presumably this also for smut, but we won't go into that here.)
The Google search engine offers standard and advanced search capabilities -- I almost always choose the advanced -- and has some customization options, which you can find by mouse-clicking on the "Advanced Search Tips" link at the top of the advanced search page and then looking at the links in the left sidebar. The "special features" link in that sidebar also points out some intriguing possibilities, but I've tried none of them, because I'm stubbornly set in other ways of doing the same things. I did, however, set up a Google "browser button" for myself, which simplifies initiating Google searches. I can either highlight a word(s) on a web page and then click on my browser button, or I can click on the browser button first and then manually type my search word(s). Then it's just a mater of clicking once on the "OK" button to start the search. Instructions for setting up a browser button of your own are in that same sidebar on the left hand side of the page you get when you click on the "Advanced Search Tips" link at the top of the advanced search page.
The Google links:
Standard Google search page: http://www.google.com/
Advanced Google search page: http://www.google.com/advanced_search
Advanced Search Tips from the Google web site: http://www.google.com/help/index.html. Don't forget to browse the links in the left sidebar.
Google tutorial from Sprintmail: http://home.sprintmail.com/~debflanagan/google.html.
The Sprintmail tutorial site also has tutorials for all of the other major Internet search engines and a slew of information on using any or all of them. Follow the links at http://home.sprintmail.com/~debflanagan/main.html
The US Government's own smut sites: