My family uses google calendar for this purpose.. it works great, and is probably the best solution out there; just remember to take some time while at a PC to set up the calendar sharing features.. in my family, my wife, daughter, and I all have smartphones, each with our own google account, and two younger children without phones. We have it set up so that all three google accounts have 5+ calendars shared between them (we also have calendars for finances / bills), with my wife and I both having permissions to create / modify / delete on all calendars, but the kids can only modify their own. The google calendar is nice, because you can even share it with the extended family so that they can easily drop in on soccer games, etc when they have time.
Many don't like the default view of the Google calendar app on the phones... I personally find the scrolling calendar widget from the home replacement app, Launcher Pro+, one of the best. It is easy to switch between month and agenda view, and both views allow for easy visuallization of appointments; "Simple Calendar Widget" is another of my favorites (I prefer to have a full calendar view right on my homescreen so that I don't have to open an app).
I did try jorte for a brief period, but personally found it to be a little too cluttered (..although it does have more features).