Ok, let's see...
The schedule for birds is ALWAYS a solar one because they are photoperiodic, a long word that means that their bodies know when is time for what from the type and length of light they are exposed to (you can research avian photoperiodism, avian endocrine system and avian reproductive system). This means that they cannot be exposed to artificial light before or during dawn in the morning, or after the sun is halfway down to the horizon in the evening (this allows their bodies to follow the seasons so they would not be in breeding season all year round, year after year).
Then you have the routine you set up for daily interaction which accomodates your own activity schedule and that is up to you BUT the best time for you to interact with them is after breakfast and before the noon rest because that's when wild birds do most of their interaction, bathing, etc.
There is only one thing that you need to keep in mind for achieving a good relatioship with a bird and that is never to have any expectations. I know that this, as simple as it sounds, it's actually the hardest thing because we all tend to have a number of things we expect from a pet but, with parrots, nothing is ever a sure thing so the less you expect, the better you and the birds will be.
Yes, it's perfectly normal to be nervous! I am nervous myself whenever I get a new bird and I have over 25 years and hands-on experience with A LOT of parrots so don't worry for one single second about this.
I don't know of any website or book that you can use... The truth is that most bird sites are more geared toward what I call 'fluff' than actual scientific knowledge and quite useless when it comes to solving a specific problem because you have all these uninformed people giving you their opinion and it's hard to figure out who is right and who is wrong. And I have never found a single book that is any good in terms of husbandry guidelines... you can get Michael's book on training but I would be very careful about applying his teachings (you need to wait until you bond with them before you start training and I do not and never will recommend training a hungry bird).
And yes, I agree with you, your friend is not a good bird keeper... if she was, she would allow them to come out to fly. It's a bit hard to get the little ones used to going back into their cage on their own but it's a matter of timing it just right (I let my budgies out very early in the am and only for the couple of hours it takes me clean all the cages and put fresh water and food in them but, if I let them out later, it would be VERY hard to get them back in because they only go back in because they are hungry for their breakfast
).
Look in CL for a pair that needs rehoming, if you are patient and check every day, you should be able to find one or two separate birds of opposite gender that need a good home. And, once you do, come back here and we will guide you step by step.