Setting time aside to disciple your children is so important. Sure, they will learn much by just watching how you live and attending church with you...but there comes a time when you need to open the Bible at home together. I realize that this is easier said than done. Satan has an endless number of excuses ready to offer up.
One of the things that had our family "stuck" for a while was the fact that our boys were getting older. We wanted more that just Bible Stories (though a wonderful choice for younger kids!) or devotions with just a few paragraphs and one Bible verse. We wanted the teaching to go further. My husband searched and searched and found I Want to Teach You What I Believe from Victorious Christian Living International. We have been very happy with it. There is no prep work required, yet the teaching is thorough. My husband teaches from the notebook (not sure if those are available anymore...looks like just the cdrom.) and writes on our chalkboard notes for our boys to write in their spiral notebooks (just ones you get at the store...no special book is needed). The boys have enjoyed this "teaching time" with dad, as mom teaches them all day long!
When we first started family devotions, we tried doing them in the living room, but we found that once we all scattered from the dinner table that it was difficult to get everyone back together again. My husband had the idea to have them around the dinner table. In our last home, we had a dry erase board in our dining room. This really didn't go with my decor, but was worth it, of course. In our new house, it works out to have an actual chalkboard near the kitchen table...and it goes with my French Country/Coffee Bistro decor! :)
I have shared only one idea source for family devotions. There are plenty out there, just ask God to lead you to the right one. In fact...all you really need is the Bible!!