I just handed off a notebook to a friend of mine who has young children. It was from when my children were young and we don't need it anymore. In it I kept all sorts of ideas for games, projects, craft ideas, snack recipes, anything to do with the kids. A lot of those ideas became family favorites like how to make a mini-journal out of one slip of cut/folded paper or how to make origami animals. But now she can use it and I'm on to making other notebooks.
As adolescents my kids aren't that into projects with mom but I have some ideas for when they do want to do stuff together. Fun crafts, interesting projects, little games, they're all in there, just geared toward bigger kids.
I have a project notebook full of decorating ideas for the house and future houses. I go through it regularly and reshape it room-by-room to keep the ideas flowing and to see where my 'home thoughts' lie.
I also keep a separate notebook with the girls awards and certificates and clippings from the newspaper. I'm not one of those moms who keeps a lot. School papers? gone. Projects from elementary school? gone. I just don't have space for all of that (well, I do really, but it's overwhelming to try to keep up with all of the paperwork from the past let alone all the junk we own).
Each of these notebooks doesn't get added to very often but when I need them they are there and that works for me.
To see what works for other folks head on over to Rocks In My Dryer.