I have lived in a house on a month to month lease for more than a year. My ex moved in about 8 months ago
we broke up 3 months ago, she started sleeping in the guest room. I gave her some time to "get things together" but didn't understand she had no intention of leaving. I let her bring her cats over so they could go to the vets and they never left either.

I understand I could start the 30 day evict process. There is no written agreement, she has never given me a dime either.

My lease states I may not sublet the house. Does that help me get her out faster?
I have told her she must leave.
Can I still have people visit the house freely?
Can she? I do not want anyone she knows in the house.
Can I boot out the cats? Are they part of the sublease? My lease forbids pets.
The landlord loves me as a tenant and wants me to stay. Is there anything they can do to help? They never authorized anyone else living at the house.

I'll end up with an attorney, but want a better idea of my rights in this case.

Have you browsed through the information in LawInfo's Free Legal Resource Center to learn more about your issue yet? See: http://www.lawinfo.com/consumer.html and http://resources.lawinfo.com/en/index.html. You can certainly try to speak to a lawyer to determine what legal options may be available. In the meantime, you may be able to learn more on your own. Search the "Free Legal Resources" tab, or browse the Consumer Resources. Good luck.