Some users might prefer do whitelist websites on a per-site basis and that is perfectly reasonable. Others prefer to whitelist all bookmarks at once which is not doable in the options of the add-on. The author of the add-on however has created a script (discovered at Firefox Mastery) that takes the contents of a bookmarks file and creates a whitelist file out of it.

The process itself is pretty simple, users do need to have access to their bookmarks in html format though. Firefox 2 users can simply access the bookmarks.html file in the Firefox profile folder while Firefox 3 users need to export the bookmarks into html format first which can be done in the Bookmarks Manager.

Once the file is available it has to be opened in a text editor. All contents need to be copied and pasted into the script on the Adblock Plus website.

That script will generate a whitelist file for Adblock Plus which can be imported in the preferences of the add-on.