Point-of-view is one of the chief tools you have for controlling your reader's experience of the story, and their reaction to it. So I have blogged about it a good deal, mostly in the four posts in the Point-of-View and Narrators series. This Bitesized series post is a quick check-in with a few of the questions which crop up most often.
1) Readers don't only get involved with the viewpoint characters and no one else.
Think about it: there's no equivalent of point-of-view in films and plays - everyone is seen from the outside - any more than there is in real life. But that doesn't stop us empathising with characters on stage and film, and their fate in the story can still matter to us hugely. So although choosing the point-of-view character/s for a story is an important decision, it doesn't cut the reader off from others who matter. You just need to make put those characters in situations which make us care about them, and make sure they act and react so we do.
And bear in mind that if fiction is built on conflicts between what difference characters want and need (which it is), then a story where we not only understand but sympathise with two, opposing, sets of wants-and-needs, is going get a whole lot more interesting for the reader.
2) Readers don't only think what the viewpoint character thinks.
Given something like this –
When Andy went into the station, he immediately found himself surrounded by commuters rushing to catch trains or get to work, while others stood about, checking the departures board or sipping coffee.
— we are technically in Andy's point of view more than anyone else's ("he found himself"). But we don't seriously doubt that these events, in this story-world, are objectively the case; most readers, present in that scene, would experience it in a similar way. But this is different:
At the station, Andy stumbled straight into the commuter-ants pouring across the concourse, helplessly caught up like a leaf in the stream as they made for the office or the train, drank coffee or stared at the departure board: each one an automaton obedient to the demands of its working life.
Because this is more strongly, subjectively flavoured by Andy's personality, the reader has a parallel knowledge that this may be true to Andy's experience, but it's not necessarily true for everyone; another character might find the bright buzz of the place, the brief human contacts, amusing or energising.
Remembering this is also useful if you're worried about a viewpoint character having views & reactions which readers might find offensive. The more strongly the writing is coloured, even distorted, by those objectionable views, the less most readers will buy into them, or think that you do. Though you could belt-and-braces with another character's, different, take on things.
3) Readers don't mind at all if you move point-of-view within a scene.
Yes, those of your writers' group who believe that moving point of view anywhere except at a scene break is "head-hopping" may tell you it's against the rules. But there are no rules, only tools, and provided you do the move well, taking the reader securely and smoothly with you, the rest of the world really won't care - if, indeed, they notice at all.
What readers don't like is a point-of-view move done badly, so that they're disoriented or confused, or don't know who it is who feels the station as an ant-heap. More on how to move point-of-view successfully here.