Wash w/ dish soap & water and then sterilze - each use. I have 4 or 5 going at a time so one is dry when I need it. (air dry with a clean dish towel over top)

Avent's baby bottle steam sterilizer is super easy.

The new Avent model has a new 2 nd cycle that keep sterizing for 24 hours - but then they are wet - although sterile - not sure about that. I use cycle 1 .

http://www.aventamerica.com/products/warmerssterilizers/warmerssterilizers_iq24.asp