Well, everything airship. The internet is, of course, the first place to begin reading. Read as many different websites as you can stand. Much of the information will be repeated many times over. Then start finding books. Find physical books in used bookstores and online. Many of the books I had to copy from research libraries have now been reproduced or are available online.
Don’t limit yourself to non-fiction. Many fictional stories have basis in fact. Jules Verne is a great starting point. There are also many current books in the Steam Punk genre which are entertaining. Here, it is important to note that physics is usually abandoned. Still, it is the dream of living the aerostation life and worth the time to dream.