Announcing New Manager

Quick question -

a) Should the new manager be present in a meeting where the current manager is announcing about the new manager change to the team? Especially when the new manager is from a different group and taking up this additional responsibility.

b) In initial days, what tips or best practices should the new manager keep in mind while managing this new group he/she has just taken over.

Any tips, experiences or links would be appreciated.

Thanks for everyone's help.