The Highpointers Club doesn’t have a definitive online guide. There are plenty of books available at the Highpointers Merc including guidebooks by HPC members: Holmes, Wingers, and Zumwalt. Sources with current information are two interactive sites: summitpost.org and wikipedia.org.
Additional resources can be found on the “Downloads & Links” page. Here we have a curated and categorized list of links on various subjects like “trip reports”, “geology”, etc.