You should apply for your kids proof of citizenship if you haven't already, see
http://www.cic.gc.ca/english/citizenship/proof.asp You can do that at the Canadian embassy where you live.
Bringing your husband over as a house husband without sponsoring him for PR is not really a good idea for future prospects. First of all, he can only stay as a visitor for 6 months at a time but another thing, if he wants to get a part time job or study, he would need a permit and he would not be able to get health care and in many provinces, he would not be able to get a drivers license while on visitor status.
To sponsor him for PR, you can actually start before you move to Canada but then you would need proof that you will be moving to Canada when he gets his PR. You could also start the application after you move to Canada with him on visit status. If it takes longer to process than the 6 months, he can apply to extend his visit status.
If you apply from within Canada, you would have a choice of applying inland or outland. Inland generally takes longer and doesn't have appeal rights as well as it is not advised to leave Canada while it's in process while outland has the downside that if an interview is required, he would have to go back to his homeland for it.