Sign your kids up for magazines. This branches off of last week's quick literacy tip because...everyone LOVES getting mail. Not junk mail, real mail!
Here's a hint: get a subscription in a subject area they like to know things about. Generally, kids' magazines are put together by educators or those who know child psychology. Lots of things are done right - flow of the layout to encourage readers, vocabulary is strong but not unreachable and the content is interesting to kids. The only one on this list that is not for kids specifically is USA Today Sports Weekly. Their reading level tends to be right around a 5th grade reading level. Many schools already have subscriptions to National Geographic for Kids, but if your reader loves it, there's no reason you can't have it at home too!