The basic idea is the same - completed/uncompleted action. An iterative action (repeated multiple times) is considered uncompleted, although it may be completed for each single iteration, but the whole action is still ongoing as more and more iterations will occur.

So, if you mean iteration in Future (like with "каждый день" etc.), you always need imperfective (the compound form with "быть"): Я каждый день буду читать газеты. (Прочитаю is grammatically impossible for this occurence).
Otherwise, the choice is based on completeness.
Two more examples for you to compare:

1. - Что ты будешь делать сегодня вечером? - Я буду читать книгу.
It tells us what you are going to be occupied with: you will be in process of reading. It does not tell us if you are planning to finish the whole book this evening. Probably, it will take many evening for you to read the whole book, but you are just going "to be reading tonight".

2. - Я дарю тебе эту книгу.
- Спасибо, я её обязательно прочитаю.
Now it is perfective, you see? You promise that you will read the whole book, not just a few pages of it.

There are many nuances though. But the basic idea is the same as in the past tense.

PS Although it is very hard to explain the whole concept of the verbal aspect in a few words, I usually use the following explanation:
The aspects help you identify how you VIEW the action.
Imperfective - you view the action "from inside the very process", i.e. your "reference frame" is a moment within the period of action duration.
Perfective - you view the action "as a whole" "from outside", i.e. your "reference frame" is a moment beyond the period of action duration.

If you get what I mean I hope it can help. Try to apply this explanation to the examples above.

E.g.:
Я буду лечить людей (imperfective) - is a permanent state of your ability to treat people. You consider it as an on-going activity. When this time comes (in Future!), you will start treating people: tomorrow, after tomorrow, the other day etc. etc. So, you imagine yourself "in state of treating people".
Я вылечу человека (perfective) - is a whole single event you consider it from outside (when someone is already healthy thanks to your treatment). Here you focus on the result state, not on the process. When this time comes (in Future!), the person is finally well after all of your treatment. So, you imagine yourself "after successful treatment of a specific person".