Google is the leader when it comes to search engines. With the google search engine here are some techniques to get various kind of usual information.
# (site:) - Domain restricted search. Shows how many URLs are indexed by Google from a directory including all the sub domains. Also shows sites of specific top level domain.
e.g; site:www.google.com, site: google.com, site: lk
# (inurl:) -Narrows the search to urls with the given word.
e.g: inurl:cricket This gives urls which contain word cricket
# (intitle:)- Narrows the seach to urls where title of the page contains the given parameter
e.g intitle:seo - This gives search results which contain seo in the title
# (inanchor:) -Narrows the seach to urls most powerful backlinks which contain the the given parameter
e.g inanchor:srilanka
# (intext:) - Find the pages with most optimized relevant body text.
e.g intext:seo
# (ext:)/(filetype:) - Seaches pages that ends with given extension
e.g ext:py , filetype:py
# (related:) - Gives similar sites which they are linked to.
e.g related:www.cricinfo.com
# (info:) - Gives information about a site such as web pages that are similar, web pages that link to the site, web pages that contain the given term etc.
e.g info:www.example.com
# (cache:) - See what the page looks like when google crawls it.
# ~keyword - Show key words that google think are related
e.g ~car ~rentals - Will give results that related to zoo car and rentals
# "" - Gives results with the exact words withing the quotes.
e.g "I love my country"