For future events I put in only things that have to be done on a specific day, or that I might want to do on a specific day (events, shows etc.)
During the day I update my calendar with what I actually did that day so I have a record of what I worked on. I print a hard copy at the end of each month and file it in reference (backup in case my electronic calendar dies).
For both types of items on the calendar I categorize them with my major context categories.
I'm using Palm Desktop on a Mac and a Treo for my calendar.
For me mixing in informational stuff doesn't work, it's either something I have done or something I have to do or something I may attend, sheep willing. The last category is often fun stuff that may or may not happen depending on what else occurred that day but it's only going to be possible on that specific time. An example is a potluck picnic for a group I belong to. If things work out well we'll go, if we get swamped we won't but I can't do it at another time, it's that day/time or not at all.
Does that help?