Hi
As you probably know, you will work one month on one off. On your month on, you will have a normal roster which now will be a maximum of 4 duties between days off. As we now have the Carmen bidding system it should be easier for you to bid for the type of shifts that suit you more. I'm not sure of how well its working as I am on Maternity myself but some people seem to be getting what they want, others not. All I would say, is make sure you get someone who knows what they are doing to help you initially. I would imagine you will get trained on it on your rejoiners course.
You also have the choice of whether to do night stops/long haul or not which you ca opt in or out on a monthly basis. Hope this helps, good luck.