hopefullysoon, you send the application for sponsorship and PR all together, it gets sent to Mississauga where they process the sponsorship part and make sure everything is signed and everything is there, then once approved it's sent to buffalo where they process the PR part.
As far as the visiting visa part, you tell them you're visiting, they'll ask how long or when you plan on returning and based on what you tell them and evidence such as proof that you applied, your husband was approved as a sponsor, how much money you have saved to provide for yourself, they then issue you a visa for how long they want, it's not always 6 months. but once in Canada you can apply for the extension when its time too.