In the books, Harry has a snowy owl named Hedwig who is a messenger of letters. Play off the owl theme as you are reading the books, by setting up an Owl Post. Do this by posting a paper owl with a flap for the beak. Whether individually or as part of a group, each week write the total pages you have read on a sticky note and place it with Hedwig as a message of how far you have gotten.
Read each book and then watch each movie right after. This is an activity in which everyone can participate and which promotes a spirit of reading as a group. Once you have read a book and then watched the corresponding movie, have everyone takes notes on the differences and similarities. Bring everyone back together once this is done and compare observations. Also discuss which elements individuals preferred in the book and which the group felt came alive better in the movie. Book vs. movie debates will stimulate group enthusiasm and lively literary exchange.
There are many plot high points, memorable characters and well known quotes from the Harry Potter books. Jot them down as you read the books and create flash cards. Use these for a quiz game with questions such as who said a particular quote or in what location did something happen. Cards, and making cards, will not only help you with reading retention but bring back memories of the books and make you want to read them all over again.
A literary treasure hunt through the world of Harry Potter is a reading activity with prizes at the end. Divide up into groups and give each group a treasure that it can hide. Write each letter of the hiding spot on a separate index card, and on the flip side, write a question about a detail in the book with the page number. Place all the cards in a stack with the questions face up and exchange with another group. To get the letter, a player has to answer the question correctly, which may mean going back to the book. Unscramble the letters and find the prize.