How to change Django Admin Custom list field label

To display the ISBN you could make a custom field like this:

class BooksField(forms.ModelMultipleChoiceField):
    def label_from_instance(self, obj):
        return obj.isbn

There's a CheckboxSelectMultiple for the ManyToManyField but it doesn't display correctly on the admin, so you could also write some css to fix that.

You need to create a form for the model, and use that in your admin class:

class AuthorForm(forms.ModelForm):
    books = BooksField(Book.objects.all(), widget=forms.CheckboxSelectMultiple)

    class Meta:
        model = Author

    class Media:
        css = {
            'all': ('booksfield.css',)
        }

class AuthorAdmin(admin.ModelAdmin):
    form = AuthorForm

As of Django 1.7 you don't need to override templates. You can now implement site_header, site_title, and index_title attributes on a custom AdminSite in order to easily change the admin site’s page title and header text. Create an AdminSite subclass and hook your instance into your URLconf:

admin.py:

from django.contrib.admin import AdminSite
from django.utils.translation import ugettext_lazy

class MyAdminSite(AdminSite):
    # Text to put at the end of each page's <title>.
    site_title = ugettext_lazy('My site admin')

    # Text to put in each page's <h1> (and above login form).
    site_header = ugettext_lazy('My administration')

    # Text to put at the top of the admin index page.
    index_title = ugettext_lazy('Site administration')

admin_site = MyAdminSite()

urls.py:

from django.conf.urls import patterns, include
from myproject.admin import admin_site

urlpatterns = patterns('',
    (r'^myadmin/', include(admin_site.urls)),
)

Update: As pointed out by oxfn you can simply set the site_header in your urls.py or admin.py directly without subclassing AdminSite:

admin.site.site_header = 'My administration'