Books Children Love by Elizabeth Wilson--This is my favorite guide to children's literature. The books are categorized by subject (such as animals, Bible and moral teaching, biography, crafts,history, geography, humor, language, etc.) and then the literature category is further broken down into three levels. Each book listed in this guide has a brief summary. I do not go to the library or order books online without this book in hand!
How to Grow a Young Reader by Kathryn Lindskoog and Ranelda Mack Hunsicker--another guide for children's literature. This book has more general information than the above book. It also lists the books by category, gives a brief summary, and also gives a grade level for each book.
Who Then Should We Read by Jan Bloom--This book is different the than the two previous books I listed. Instead of giving a summary of the books, it provides a brief biological sketch of numerous authors, then it lists all of the books written by that author. This is a nice resource to learn about quality authors, and also to discover other books that were written by your favorite authors. The authors are categorized by their genre. This book also includes all of the books in various series (like Childhood of Famous Americans, and Landmark books), and provides reading level suggestions too.
Honey For A Child's Heart by Gladys Hunt--The first part of this book is entitled, "Using Books to Help Children Grow", and it provides information about the purpose of and benefits of children's literature. Part 2 includes booklists with brief summaries. These lists are divided into categories and also by age level.
Sonlight Catalog http://www.sonlight.com/ --I use this catalog much like I use my "reference books". I look for books by particular authors or subjects, and I read the summaries that the catalog provides. Sonlight lists its books by grade level and subject.
All of the above resources, with the exception of Who Then Shall We Read? include an extensive index. I can easily find a book in question and read the summary and suggested age level.
Now, for specific titles for reading aloud to small boys. These are some books that Clay liked at a younger age (my girls too!). In fact, they all still like these books, but I think they would be enjoyed by boys 6 and under.
Beverly Cleary books such as Henry and the Paper Route, Ribsy, Ramona the Brave, and really any of the other Cleary books too.
George Selden--A Cricket in Times Square, Chester Cricket's Pigeon Ride, Harry Kitten and Tucker Mouse
The Bears on Hemlock Mountain by Alice Dalgliesh
The Matchlock Gun by Walter D. Edmonds
Elizabeth Yates--A Place for Peter, and Mountain Born
Girls of this age usually love the Little House series by Laura Ingalls Wilder. In fact, I am currently reading Little House in the Big Woods to Leah (and Sam) at bedtime.