Meghan Wilker, the co-author of the blog geekgirlsguide.com, shares her strategy for going digital in four steps: centralize, categorize, share and automate.
Centralize: Choose one tool where you can put all the information you need. (I recommend Google, because it's free and it allows me to share while controlling my privacy.) Give that tool a test run with a handful of events. Make sure you like how it works, what it does and how it looks.
Categorize: Find a way to categorize events in your central calendar. Maybe it's by person (Mom, Dad, daughter) or by location (work, home, cabin) or some other criteria. Make sure you can filter out certain views for when you're trying to focus on just one or two categories. And don't be shy about creating extra calendars for miscellany.
Share: Share your setup with the people who need to see it, such as spouses and older kids, and give them access to make edits.
Automate: Once your calendar is humming along smoothly, figure out how to take it to the next level. For example, I started using BusySync to add and view events when I'm offline, and then synced everything with my iPhone so I can read and update my calendar no matter where I am.