<$40; 4.5*, free shipping, stand up to pro use...
The Joy of Mixology - For the enthusiast.
The Bar Book - For the new (or old) professional.
Hey r/cocktails would be probably the better place for this but I can help a little bit tool sets are covered in the wiki:
https://www.reddit.com/r/cocktails/wiki/starting_guide
Tool set really depends on how much you want to spend and include: they mention a set on amazon that I think that's around ~$70. If you want to spend more Cocktail Kingdom has sets as well but I think they start ~$100 if I recall correctly and would not include everything you might find in the amazon set.
Regarding books it depends what a little bit on what you think would be best for your friend:
If you want a book that includes recipes but also covers proper techniques etc: I would recommend the bar book by Jeffery Morgenthaler (https://www.amazon.com/dp/B00GOJT5H0/ref=dp-kindle-redirect?_encoding=UTF8&btkr=1)
If you want a book that has recipes that don't require a bunch of specific ingredients I would recommend the 12 dollar bar (https://www.amazon.com/dp/B00GU2RGPY/ref=dp-kindle-redirect?_encoding=UTF8&btkr=1)
If you want a book that kind helps organize how cocktails are recommended and related to one another Cocktail Codex (https://www.amazon.com/Cocktail-Codex-Fundamentals-Formulas-Evolutions-ebook/dp/B07911KFYZ) is really good at this.
Hope this helps, -PersianElf