That's a "B" NOC code. (8252 = 2 is "B")
Six months is what I've heard from others in similar situations if they didn't accompany their spouse. You can try before - it just seems 6 months is a preferred length of time by applicants. (I've heard a lot of people get rejected when they apply at the same time as their spouse, because there's no proof their spouse is working the job yet!)
You'll need copies of your husband's work permit, employment letter, and proof he's working (letter from employer and/or paystubs - I say get both) along with your documents and fees.
Your OWP will have the same expiration as your husband's work permit.
There are several threads (actually many, many threads) about this in foreign workers and students section of the forum. (Students can get their spouse a work permit too.) If you look around, you can find some of them. There is a lot of good information.
http://www.canadavisa.com/canadian-immigration-open-work-permits.html