I was going to say mine looks a bit like Agavegirl's but I don't bother with crowd levels.
For mine, I just made a chart using Word. Now that I have mine, all I do to update it is change the dates, update park hours, and update our ADR's. I put things like hotel confirmation numbers down below. As others have said, it should contain the info YOU find useful, otherwise it just becomes a visual jumble.
One thing I have found is that if we go say- Tuesday to Tuesday, I still have to keep the chart starting Sunday to Saturday (and make two weeks, so to speak) Otherwise it is visually confusing.
All that said, the last few trips, I really didn't touch my paper print out at all. I emailed the word file to myself, and used that a bit. Mostly I used the WDW My Magic. I mostly only consult it for: our FP+ times, ADR times, and MK hours.
With extended family they really only need three things: which park (each day), time/place of ADRs (i.e. where they need to be at 7pm), and everyone's flight info (I put that info in a second chart). MAYBE park hours/emh schedule.
Otherwise they simply ask me. We've not big on parades, and usually the fireworks are the same time every night. Epcot hours are ALWAYS 9-9. AK is almost always 9-5 or 6. HS is never a full day park for us. So really the only park everyone needs to keep track of is MK, and only days you'll be there.
As I said, the last few trips, we didn't really touch paper very much. It is just a backup. Sinc eI have the template though, it only take a few minutes to update it.
What has become VERY useful though is having a good smartphone. I use it to record all sorts of stuff. One click, and you have an electronic copy of ANYTHING: where you parked, what each child is wearing each day, receipts, ticket code numbers, any other ID numbers, transaction records.
Last time someone bumped my car - non WDW- instead of standing on the side of the road where it's very dangerous looking for paper and pen to write down the other driver's information- I just took a picture of their ID, insurance card, and car damage. (and hey, if you have a car, that could happen at WDW!)
Actually - if you DO rent a acar - ever- then a quick walk around the car when you get it- taking shots of ANY existing damage- can INDEED save you from costly false accusations later!
Also know that WDW park hours are always subject to change. so even if your spread sheet is updated just before you go, things can change. that's almost why electronic files are now better.