There are four books in the series, but I only looked at two: Plan a Birthday Party and Plan a Sleepover Party. Both include step by step instructions for planning, including a checklist, reminders on how to invite your friends without making other people feel bad, lots of suggestions for themes, decorations, and food, and, of course, reminders on cleaning up afterwards. There are also reminders of party etiquette. One, in Birthday Party was really weird - it suggested that you practice open presents and saying thank you. That really didn't seem to fit with the audience for these books, which is tweens.
Additional resources and a brief index are included at the back of the book. Each book features a few boys and a diverse group of girls. The party themes are also diverse, including sports, outdoor, makeover, and more.
One of the things I really appreciated about this series, and that moves it to the top of my list, is that the majority of the activities, decorations, and food are low-cost. Alternatives to more expensive options are suggested and kids planning a party with a small to zero budget will find plenty of options here. So many party books I've looked at are ridiculous in what they expect kids to be able to spend, but this is quite reasonable, making the books accessible to a wide variety of kids.
Verdict: These are only available in library bound and cost about $20 apiece but while I'd prefer paperback versions, these are so well-done that I think they're worth the extra money since they'll appeal to a wide variety of ages, interests and budgets. Recommended.
Plan a birthday party
Plan a sleepover party
Published 2014 by Lerner; Borrowed from another library in my consortium