Getting a resident permit after getting married to a Chinese girl

I'm from Pakistan and my Gf is Chinese , we have met many times in Thailand n Singapore and now we are about to get married in couple of Months , i wanna know after i get married to her so i can easily go china ? because she can not adjust in Pakistan and i dnt even have any family there! so me and she we decided to live in china , am i able to do any work there when i get residence permit to live with her ?
how long it takes to get residence permit and how long i can live there ?