Why Scrum and not Kanban
Core Agile principles
Scrum Process overview
How big should a (delivery) team be?
In general: Smaller is better. Amazon's preferred max team size of 6 to limit the number of communication lines between team members.
Should I split user stories into tasks?
Do it if you feel it helps development progress faster, but 2 things are no-go's:
- User stories should still be on the board,as the core measurement of progress (since users value stories because they can touch them)
- Estimations on task level are a no-go, see link below.