How can I reduce the number of queries to my PostgreSQL database?

[SR]

As a starter project for learning Python/PostgreSQL, I am building a
Books database that stores information on the books on my bookshelf.

Say I have three tables.

Table "books" contains rows for book_id, title, subtitle, ISBN.

Table "authors" contains rows for author_id, author surname, author
first names, biographical notes.

Table "bookauthors" contains two rows: book_id, author_id.

The bookauthors table links the books and authors tables.

Scenario: I have a python script which creates web page listing all
books in the database, and all authors for each book. My python script
does essentially three things:

1.  retrieve a list of all book_ids and book_titles.

2.  for each book_id, query the bookauthors table and retrieve all
author names for that book_id.

3.  display it all out as an html table on a web page.

The script works fine, if a little slow. I think that's because if I
have 50 books in my database, my script performs 51 database queries (1
for all book names; then 1 for each book). A colleague of mine
suggested that I could get away with two queries, 1 to read the book
ids and titles, and 1 to read the bookauthors table to pull in *all*
relations, and then do all the work in Python.

I think I know where he's coming from, but I don't know where to begin.
Any clues? Is there a specific name for this technique?