Most Important Tip
Try to keep your search simple. Use as few words as possible. Also, choose words that are the most commonly used and that are the most descriptive of what you want.
Example: If you want to find out what themes Mary Shelley's Frankenstein uses and you search [what themes Mary Shelley's Frankenstein uses], you will get 343,000 results. The first few websites returned include 'Frankenstein - Wikipedia, the free encyclopedia,' 'Mary Shelley and Frankenstein,' and 'Free frankenstein Essays.'
On the other hand, if you search just [themes Frankenstein], you get 623,000 results and the first few websites returned include 'Major Themes in Frankenstein,' 'Sparknotes: Frankenstein: Themes, Motifs & Symbols,' and Novelguide: Frankenstein: Theme Analysis.'
My first search (which was long and wordy) returned 343,000 hits, but those hits don't seem to be about what I wanted. On the other hand, my second search (which was more precise) returned a lot more hits than my first, 623,000, and those hits seem to be exactly what I was looking for.
Further Tips
Stop Words
Google will search for every word that you type in the search box. The main exceptions are commonly used words such as 'a,' 'the,' and 'for.' (Sometimes 'the' is not ignored if part of a proper name, such as The Cure). Other times, Google might insert a synonym in place of one of your words. Finally, Google might not include one of your words in one of your results if they have deemed that the result is relevant without it.
Case Sensitivity
Search is case insensitive.
AND
AND is automatically inserted between every word.
OR
Use OR (in ALL CAPS) to tell Google to allow either one of two or more words. Example: If you search ["polar bear" OR "grizzly bear"], you'll get results about either one of these. If you searched without the OR, you'd get results that included both bears on the same site. (The symbol | can be substituted for OR.)
Phrase Searching ("")
Use quotation marks ("") to force Google to search for all of your words in the exact order.
Punctuation
Punctuation is ignored. The exceptions are punctuation used in popular terms like C++, the dollar sign ($), the hyphen (-) when it connects words (run-on, cul-de-sac), and the underscore symbol (_) when it connects words (end_of_file).
Excluding Terms (-)
Attaching a minus sign (-) sign immediately before a word will tell Google that you do not want that word in your results. The minus sign must have a space before it. Example: If you search [saints -"new orleans"], you'll get results that are about religious saints and not the football team. (You can use more than one minus sign.)
Stemming
Some words are stemmed, meaning it will search for a word and its various endings. Example: If you search [photo], Google will bring up results for photo, photos, photograph, and photography.
Wildcard (*)
Use an asterisk (*) as a wildcard to take the place of any unknown terms. Google will find the best matches to fit where the asterisk is. You can only use an asterisk to take the place of whole words, not parts of words. Example: If you search [Arizona department of *], websites for the following departments come up - Arizona Department of Education, Arizona Department of Corrections, Arizona Department of Transportation, Arizona Department of Public Safety, Arizona Department of Health Services....
Number Range
Follow search terms with beginning and ending numbers separated by two periods to include a number range in your search. The two periods can also be one sided to be used as greater than and less than. Example: A search for [women's movement 1850..1950] will find pages mentioning the Women's Movement between those years.