Keyword
Keyword is generally a slower search because it searches several variables including title, category, subcategory and description.

Title
Searches are more successful if you omit small words such as the and and. This search looks for and exact match on the words you enter.

Author
Another exact search. Usually last name is sufficient, but if you want to search on both, enter lastname, firstname. A search on king will return books by Steven King, Steven Hawkings, Barbara Kingsolver and more. On the result screen you can select an author to find all books by that specific author.