Answer by Alex Sumner:
If the operative words are “complete novice” I would say The Middle Pillar followed up by Foundations of Practical Magic (I would also have recommended “How To Make and Use Talismans” if you can get it, but it appears to be out of print).
The Golden Dawn is advanced reading, though ultimately highly rewarding.
I have to confess I didn’t actually like The Tree of Life as I found Regardie’s language rather pompous, and it didn’t actually cover anything that had already been done better elsewhere (e.g. by Aleister Crowley or Dion Fortune).
Which book by Israel Regardie would be advisable for a complete novice?