eBook on Drupal or Actual Physical book at MPH

I'm still contemplating on either i should purchase an online eBook on Drupal development or just drop by at any book store like MPH or Popular and buy it over there. Since i could not able to find any piece of downloaded doc on Drupal from my Usenext, those are the only options i have at present; buy online a new one or buy a book at any book store.

Well for the time being, as a temporary solution, i wanna explore studying the Drupal language based on documentation online at Drupal.org. It looks quite comprehensive, perhaps this could be a good reference for me before i actually buy a new one, say if i drop by at MPH.

I can access the info from Drupal.org from either the main page -> http://drupal.org/documentation or through its API site -> http://api.drupal.org/api/drupal. Both looks promising enough for me. I guess for the whole coming March, my target would be more on understanding the overall Drupal before i truly decide to buy the book.