Every individual has two senators and one representative in their state. But only the senate matters because the senate confirms appointments, and the house does not. To begin with, please call your senator today and directly state that you are not supportive of the following potential posts:
Steve Bannon, chief strategist
Jeff Sessions, attorney general
Sarah Palin, secretary of the interior
Here are the phone numbers of senators listed by state.
Senate can directly stop members of the cabinet from being appointed, as they have to approve each one. But Steve Bannon would be part of Trump's personal staff, and so the only way to stop him would be if members of the Senate blocked cabinet appointments until Trump fires Bannon. Therefore, you can still talk to your senator regarding their options regarding Steve Bannon, if you are able to get to that level of detail in your call. Read more here.