You can narrow a search, broaden a search or focus a search using Boolean operators. Since each search engine is different, check your favorite search site's help file for specific instructions using Boolean operators.
Rankings differ from engine to engine, but most list the more relevant hits first.
Relevance may be determined by how many times the search word or phrase appeared in the document or where it appeared. Check with the search engine you use most to understand its ranking methods. Why not visit your own personal Web butler, Jeeves. Ask Jeeves a questions and he will bring the information to you.