This book is costly, but can be found at many local libraries. The Writers Guide to Editors, Book Publishers and Agents is another book containing agent listings as is The Guide to Literary Agents . Links to some of these books are at the bottom of this page. You can click on the cover to read about or order these books. There are also some websites online who list literary agents which will be useful during your research phase.
Response times vary greatly so be prepared to wait.
If your work is publishable or compatible with the agents' tastes, you will get a positive response. Some agents work with a verbal contract, others require you to sign a written agreement. If you are uncomfortable working with a verbal agreement, you can always request a written one and most agents will comply. Be sure you understand the conditions and terms under which you can cancel the contract too. You can order these helpful books here by clicking on their images.