Using an on-line source for material:

Do a little research.  Look up your focus word in the Oxford English Dictionary and one other reference book [textbook from another class?  www.wikipedia.org? www.bartleby.com?.  Look up the word in both sources, copy and paste items into a wordprocessing file, and read them, marking what you believe might be useful quotes, synonyms, antonyms, information about your key word.

Location on-line: 

• Our library has the OED on-line.
• www.bartleby.com.  Click on the reference tab at the top of the page.  Search a variety of reference materials including Bartlett's and Simpson's Quotations and numerous dictionaries.

Cautions about using the Internet sources: 

• Don't get carried away with this.  You just want a little material--maybe a relevant quote or two, some synonyms and antonyms, some words that belong in the same category as yours--to draw on for the definition paragraph.  These bits of information will become some of the concrete specific information in the definition paragraph.
• Don't take the first information you come across.  Spend some time reading and thinking about what you are reading.  Ask yourself:  "How does this quote, information, etc. support or contradict what I want to say about my chosen focus word.  Make sure that your choices are relevant and can be used to illustrate and clarify what you have in mind when you use the word.