Follow these steps to generate a basic service module:

1. Create a new iap_isbn_service module and add __init__.py:

from . import models
from . import controllers

2. Add __manifest__.py, with the following content:

{
    'name': "IAP ISBN service",
    'summary': "Get books information by ISBN number",
    'website': "http://www.example.com",
    'category': 'Uncategorized',
    'version': '12.0.1',
    'depends': ['iap', 'web', 'base_setup'],
    'data': [
        'security/ir.model.access.csv',
        'views/book_info_views.xml',
        'data/books_data.xml',
    ]
}

3. Add a book.info model at models/book_info.py, with a method to fetch the book data:

from odoo import models, fields, api

class BookInfo(models.Model):
    _name = 'book.info'

    name = fields.Char('Books Name', required=True)
    isbn = fields.Char('ISBN', required=True)
    date_release = fields.Date('Release Date')
    cover_image = fields.Binary('BooksCover')
    author_ids = fields.Many2many('res.partner', string='Authors')

    @api.model
    def _books_data_by_isbn(self, isbn):
        book = self.search([('isbn', '=', isbn)], limit=1)
        if book:
            return {
                'status': 'found',
                'data': {
                    'name': book.name,
                    'isbn': book.isbn,
                    'date_release': book.date_release,
                    'cover_image': book.cover_image,
                    'authors': [a.name for a in book.author_ids]
                }
            }
        else:
            return {
                'status': 'not found',
            }

4. Add an http controller in the controller/main.py file (don't forget to add the controllers/__init__.py file):

from odoo import http
from odoo.http import request

class Main(http.Controller):
    @http.route('/get_book_data', type='json', auth="public")
    def get_book_data(self):
        # We will capture credit here
        return {
            'test': 'data'
        }

5. Add access rules to security/ir.model.access.csv:

id,name,model_id:id,group_id:id,perm_read,perm_write,perm_create,perm_unlink
acl_book_backend_user,book_info,model_book_info,base.group_user,1,1,1,1

6. Add views, menus, and actions to views/book_info_views.xml:

<?xml version="1.0" encoding="utf-8"?>
<odoo>
    <!-- Form View -->
    <record id="book_info_view_form" model="ir.ui.view">
        <field name="name">Book Info Form</field>
        <field name="model">book.info</field>
        <field name="arch" type="xml">
            <form>
                <sheet>
                    <field name="cover_image" widget='image' class="oe_avatar"/>
                    <div class="oe_title">
                        <label for="name" class="oe_edit_only"/>
                        <h1>
                            <field name="name" class="oe_inline"/>
                        </h1>
                    </div>
                    <group>
                        <group>
                            <field name="isbn"/>
                            <field name="author_ids" widget="many2many_tags"/>
                        </group>
                        <group>
                            <field name="date_release"/>
                        </group>
                    </group>
                </sheet>
            </form>
        </field>
    </record>

    <!-- Tree(list) View -->
    <record id="books_info_view_tree" model="ir.ui.view">
        <field name="name">Book Info List</field>
        <field name="model">book.info</field>
        <field name="arch" type="xml">
            <tree>
                <field name="name"/>
                <field name="date_release"/>
            </tree>
        </field>
    </record>

    <!-- action and menus -->
    <record id='book_info_action' model='ir.actions.act_window'>
        <field name="name">Book info</field>
        <field name="res_model">book.info</field>
        <field name="view_type">form</field>
        <field name="view_mode">tree,form</field>
    </record>
    <menuitem name="Books Data" id="books_info_base_menu" />
    <menuitem name="Books" id="book_info_menu" parent="books_info_base_menu" action="book_info_action"/>
</odoo>

7. Add some sample book data to data/books_data.xml (don't forget to add cover images to the given directory):

<?xml version="1.0" encoding="utf-8"?>
<odoo noupdate="1">
    <record id="book_info_data_1" model="book.info">
        <field name="name">Learning PostgreSQL 10</field>
        <field name="isbn">1788392019</field>
        <field name="author_ids" eval="[(0, 0, {'name': 'Salahaldin Juba'}), (0, 0, {'name': 'Andrey Volkov'})]"/>
        <field name="date_release">2017/12/01</field>
        <field name="cover_image" type="base64" file="iap_isbn_service/static/img/postgres.jpg"/>
    </record>

    <record id="book_info_data_2" model="book.info">
        <field name="name">Odoo 10 Development Essentials</field>
        <field name="isbn">9781785884887</field>
        <field name="author_ids" eval="[(0, 0, {'name': 'Daniel Reis'})]"/>
        <field name="date_release">2016/09/25</field>
        <field name="cover_image" type="base64" file="iap_isbn_service/static/img/odoo.jpg"/>
    </record>

</odoo>

After installing the module, you will see a new menu with book data, like the following: