Help on searching
You can search for any book available in Open Books by title/author/tag/genre/type/price/etc. Rather than boring you with lots of technical details about the advanced features of searching, I'll start with a few examples that get progressively more sophisticated.
|Foundation Asimov||Matches any books that has the word "Foundation" and the word "Asimov" in any of its metadata|
|title:Foundation or author:Asimov||Matches any book that has the word Foundation in its title or "Asimov" in its author|
|series:Foundation and author:Asimov||Matches any book that has "Foundation" in it series name and "Asimov" in its author|
|genre:Horror and price:<2||Matches any book in the Horror genre whose price is less than $2|
|genre:Horror and not publisher:Harper||Matches any book in the Horror genre that is not published by Harper|
The complete list of fields you can search on is: title, author, tag, type, series, genre, publisher and price
For the technically minded, you can also use regular expressions in your searches by prefixing the term with ~. You can also construct boolean expression with the and, or, not operators and parentheses. In that, the search language is very similar to that used in calibre.