I have been an activity director full-time for about 10 weeks, so I certainly feel your pain when it comes to getting help from the other staff. We have some staff who will always help me out when I ask them to...but it has taken some time to gain their trust. Sometimes it helps to just sit down and listen to the CNA's and other staff. I have heard stories about the last several Activities Directors, and have kind of pieced together what traits and characteristics the staff liked and didn't like. Ultimately, they have known the residents longer than I have, so when they suggest things that have or have not worked, I really try to take that to heart...the other thing that I have tried to do is help out with the things that I CAN do for them - helping take residents to the dining room so that the CNA's can get people ready, helping to pass trays at lunch for the residents who don't come out, things like that. The "I'll scratch your back if you scratch mine" really does work, because it shows that you are not asking them to help you when you won't do something for them. Little things go a long way.
It will take a little time, but be patient. You are probably not the first person that they have seen come onto the stage, and, depending on the reasons and the circumstances that the last person left under, they are probably a little leary of you. Don't make promises that you aren't willing to keep, and be willing to listen when someone gives you some advice of their own. They usually know what they are talking about!