Best way to save user profile details android app

view story

http://stackoverflow.com – I'm creating an app which has several users. I've created an object (user), which holds more details (name, age, custom objects etc). Because I have a custom object, I know it'll be difficult to use shared preferences. What would be the best way to store the users data? I've looked into SQLite, but I can't find a way to save custom objects into SQLite? Any advice would be appreciated. (HowTos)