Can iCloud or some combination of Apple IDs help me do this?

Planning to get a new iMac whenever they become available to order. I'll be using it as the family computer and I'm hoping while I'm setting it up that I can also reconfigure some of my family's accounts to get all of our devices working better together.

Here's what I'd like to do. There are three of us (myself, my spouse, our daughter). We've all got different Apple IDs and we've bought music/apps/etc with those different Apple IDs over time. In addition to the 1 iMac we'll share, each of us will have 1 iPad + 1 iPhone or iPod Touch. I'd like us to be able to share all of our music, apps, movies, TV shows, and books across all our devices. I'd like to keep Mail, Notes, Messages, Safari tabs separate for each of us. It would be great if we could share some photos/videos but not all, as well as some Reminders lists and Calendars, but again not all.

How close can I get to that? Whatever approach gets me there, how would I back all of this up? What options would I still have for parental controls on my daughter's devices? Is there a good how-to book that could guide me through what I'd need to do? Or in this situation is it just best to make an appointment at an Apple store?

Thanks in advance!