Take a look here : http://dev.evernote.com/doc/articles/note-sharing.php (Check the "Listing All Shared Notes in an Account" part).
Do you have some code you could show ?
Here is some code that should do the trick :
import evernote.edam.notestore.NoteStore as NoteStore
from evernote.api.client import EvernoteClient
from evernote.api.client import Store
from evernote.edam.notestore.ttypes import NoteFilter, NotesMetadataResultSpec
auth_token = "YOUR TOKEN"
client = EvernoteClient(token=auth_token, sandbox=True)
noteStore = client.get_note_store()
# get linked notebooks
linked_notebooks = noteStore.listLinkedNotebooks(auth_token)
linked_notebook = linked_notebooks[0]
# shareKey for the first notebook
shareKey = linked_notebook.shareKey
# get the right noteStore
note_store_uri = linked_notebook.noteStoreUrl
shared_note_store = Store(auth_token, NoteStore.Client, note_store_uri)
# authenticate to the linked notebook
auth_result = shared_note_store.authenticateToSharedNotebook(shareKey,auth_token)
# get the share token
share_token = auth_result.authenticationToken
updated_filter = NoteFilter(words=' ')
offset = 0
max_notes = 40000
result_spec = NotesMetadataResultSpec(includeTitle=True)
result_list = shared_note_store.findNotesMetadata(share_token, updated_filter, offset, max_notes, result_spec)
print result_list