Read Firebase data using Angularfire2


I am a beginner in Ionic2 and AngularFire2. I am building a multipage project to display data from Firebase.
It can be done easily by using AngularFire module with af.database.* but I checked in few websites that using AngularFire module on every page is not recommended. Instead, we should Services to fetch data.
I am not able to get any proper tutorial or information regarding how to use Services.
Could anyone please point me in the right direction.