The manual is divided into sections. Each section has a table of contents page with links to the different topics in it.
To search in a file, click on the section link to open that document, and then click Control + F. Type in the word you are looking for and hit Enter.
You can search and/or print the entire manual by clicking on the "Entire Manual - printable" link.
The general reference section has a number of how-tos in it, such as How to Search and How to Hide a Story Folder, as well as information about what the different icons mean.