"The Horse's Mouth"
Start by talking to people who have been involved with your subject or who have knowledge on the topic. Most people enjoy talking about their areas of expertise and you can learn much in this firsthand way. Always ask them for other contacts and references that may help you with your research.
Text Books
Start with any texts you have on the subject:
- use the Contents and Index to get a brief overview of the topic
- use the Bibliography at the end of the text to get some ideas for further research
The Library
Visit your local library — you'll always find excellent background information for your subject and the librarians will be able to direct you to up-to-date resources.
Check out the catalogs in the library of your choice — as well as telling you where the book is on the shelves, the catalog can also tell you whether it's worth the effort of finding it. If your topic is communication and a reference book was published in 1950, it's probably not going to be of much use since most of its findings will be out of date.
When you are using the catalog, look for specific headings, not general ones — this will save time.
Look for the Bibliographies in the Reference section of the library — these will tell you what other books are available.
Don't forget specialist journals and magazines on your topic — libraries will also have a catalog of these.
The Internet
The Internet has made it incredibly easy to find information on everything, and you can start your search at the Internet Public Library.
Bartleby has a collection of references online.
Use any of the major search engines, such as Google or Yahoo, to find specific details. You'll get more relevant results if you enter a phrase rather than just one word. So try "medical inventions that improve surgery survival rates," not just "medical inventions."