For water births:
-Spacious blow up kiddie pool

-Attachments to fill from the hose or tap
-Pots to heat water in
-Water thermometer
In general:
-Sitz bath
Things to think about
:
-What you will want to wear
-Appointed jobs the people present can do to make things easier
-Photos? Videos?
-Who will come see baby and when
-Personal coping methods; distractions like movies? Music? Reading?? Massage? Focus points? Etc