Additional Word Press Sites, Domain & Hosting Support

I would like 3 additional websites set up using Word Press. I already have one Word Press site set up that I'm using. This request is for 3 additional Word Press websites. I have purchased the 3 domain names and I have hosting through DreamHost. I am not sure if the hosting is currently set up correctly for each of the 3 domains. I have a specific plugin I want to use for each of the 3 websites through Word Press. I wish for this to be installed and ready to use for all 3 websites. I want to be able to log into each Word Press website and be able to create and modify all 3 additional websites with ease. Possibility for ongoing Word Press, Domain and Hosting work.