I am on a unit at the moment (well right now I am at home on leave but you know...) and have been on one for much of the past 5 months.
It is pretty low key, there are TV lounges, activities (I am on a woman's unit so the activities are very female - pampering, sewing, arts, DVDs, outing to local shops).
Depending on how you are most people are allowed out and about on leave. I spend a couple of hours at home most days. It is not like the films, you don't sit around doing group therapy, you don't have lots of talking therapy. The nurses are there if you need to chat, you have a review with the psychiatrist once a week, you might see a psychologist once/twice a week (my unit has one based there). Nothing is really forced on you, although you are encourage to eat / drink / wash / sit in communal areas.
For me it is a space to recover and re-coup. At home I was just self harming more and more and it took over so in many ways it is a huge relief to come somewhere to be safe and that is treatment in itself! I also find it really helpful having people there 24/7 to talk to and the unit I am on is good but it took a long time for them to get to know me and my needs and to develop a decent relationship with them.
When I was first admitted in April they also set up community services for me, and started my community based psychotherapy when I was IP. This admission I have re-started some medication and one of the reasons for the admission was to let the medication start to have some effect prior to discharge.
Don't know if this helps.