HOA's & CDD's will vary depending on neighborhood - in the Spring Hill subdivisions, there are no HOA or CDD fees. But it's important to note that Spring Hill is a series of subdivisions, not a town or city and there are many neighborhoods WITHIN the Spring Hill Subdivisions that WILL have HOA & CDD Fees.
Overall, these are not "quick and easy" questions as there are many variables that can come into play. If you'd like, feel free to contact me at http://www.HernandoLuxuryHomes.com and I'd be happy to get as specific as you'd like with regards to whatever properties in particular you find interesting.
I hope this was helpful!