Possible Clues:

• Library needs
• Items found on library shelves, and what are literally found in each set of circled letters
• Literary props
• Supports for some volumes, and a hint to the circled letters
• Supporters of the printed word?
• They keep spines upright ... or the first and last two letters of the starred clues' answers, in two ways?
• Volume control?
• Supporters of all varieties of literature
• Simon & Garfunkel album, and a hint to what can precede and follow the halves of the starred answers
• Title holders