Have you tried Google’s Advanced Search yet?  Adding a few search commands to your query helps you find the information you want by making your search more specific.  The advanced search helps you do this, and here are a few tips and tricks you can use in the ordinary search:

Colour code: command, example, explanation

“oxford eresources” use quotes to find a phrase rather than separate words

intitle:sciencedirect safari find pages with these words in the title

inurl:ouls libraries find URL with this word also useful for dates e.g. inurl:2009

link:oxforderesources.wordpress.com to find pages linking to this site

site:ouls.ox.ac.uk restrict results to the OULS site

labour OR liberal finds either word

labour AND liberal finds both words

related:ouls.ox.ac.uk to find similar or related pages

filetype:pdf to find a particular filetype (try also doc and ppt)

+ the script Common words such as and, how, the are usually ignored in searches . use the ‘+’ symbol if a common word is essential to your search

~pavement synonym search (this example also finds asphalt)

define:PWN find a definition. Yes, you could use a dictionary (online or otherwise), but this will be more helpful for jargon, abbreviations and new words (examples: Web 2.0, OpenURL, GWOT, crackberry).

time:oxford find the time anywhere in the world

weather:oxford will I need an umbrella today?

sqrt 9 use your browser as a calculator.  More instructions

1 GBP in EUR use Google’s inbuilt currency converter List of currency codes

Try combining some of these commands, for example: filetype:pdf AND site:ouls.ox.ac.uk