Our eight year old was the easiest child to teach how to read. Her six year old brother is the polar opposite. Once Kaelin learned the phonics chart and how letters flowed together, she just took off reading all on her own. Thus began the great hunt for longer books with appropriate content. Here are some of the books off the top of my head that she has read over the last few years:
Heidi by Johanna Spyri
The Boxcar children series by Gertrude Chandler Warner
The Five Little Peppers by Margaret Sidney
Mandie books by Lois Gladys Leppard
Books by Arleta Richardson
The Chronicles of Narnia
The Swiss Family Robinson
Eight Cousins by Louisa May Alcott
Little House on the Prairie books by Laura Ingalls Wilder
The Ivan series by Myrna Grant
Caddie Woodlawn by Carol Ryrie Brink
Happy Little Family by Rebecca Caudill
Anne of Green Gables
Sarah, Plain and Tall by Patricia MacLachlan
The Bobbsey Twins
Hannah's Winter of Hope by Jean Van Leeuwen
The Little House series
Some of these books, the Narnia series for example, contain topics that you will have to decide when you want your child made aware of. These are things like peril, orphans, war, communism, consequences of moral choices, smoking, etc. We gave these books the okay because we feel the topics are dealt with in an appropriate manner (Eight cousins talks about the effects of smoking a pipe, the character in the Mandie books learns about lying), as opposed to glorifying the inappropriate behavior.
I can also recommend with some caution the American Girls series of books. It seems that since the maker of Barbie bought the company, it has gone south. We enjoy some of the earlier books.
Of course, previewing books your child is reading, screening their library selections, and keeping a running dialogue of what they've read and the topics is a wonderful idea.
We enjoy ordering our books through the inter-library loan system, scouring rummage sales, thrift stores and used books sales in order to build a nice home library.