How can I make my class iterable so I can use foreach syntax?

You need to implement the Iterable interface, which means you need to implement the iterator() method. In your case, this might look something like this:

public class BookList implements Iterable<Book> {
    private final List<Book> bList = new ArrayList<Book>();

    @Override
    public Iterator<Book> iterator() {
        return bList.iterator();
    }

    ...
}