"The greatest myth that exists about meetings is that they are inherently bad." -- Patrick Lencioni in "Death by Meeting"

The real problem is not meetings themselves, but that most meetings are run ineffectively. Contrary to what one might expect based on the title, "Death by Meeting" recommends having more meetings, but gives guidelines on how to run them effectively.

Got a new job in May so slowed me down, but got through around 8 this year.

I'm a Lencioni fan:

Death by Meeting -- Describes 3 types of meetings

Getting Naked -- Describes how to consult

I'm also a Marshall Goldsmith fan:

What Got You Here Won't Get You There - Once you get beyond a Director level with some mistakes, read this book

Mojo, How to Get It, How To Keep It - Another "look yourself in the mirror" book

Also:

21 Irrefutable Laws of Leadership - John Maxwell. A little prod to act more like a leader.

Ready Player One -- Ernest Cline, Great Young Adult Book. Escapist fantasy.

Every Shot Counts -- Mark Broady, Statistical Look At Golf, but has some smell of Kahnemann

To Kill A Mockingbird -- Timeless Classic I Never Got To. Loved Atticus. I won't read a Watchman if it spoils my view of what Atticus was all about.

Started But Not Finished:

Business Dynamics Thinking -- Sterman (out of MIT). I need to take off work to read this 'cause it is so massive. Basically it is control theory applied to business modelling. However, I am convinced if somebody can apply these models, it really is the best competitive advantage. However, too people willing to stick with it.

How to Measure Anything -- Douglas Hubbard. Sort of makes me mad because it is so commonsense, yet most businesses don't apply this commonsense approach.

Here's the list of books I've been recommending new managers and leaders read:

Small Unit Leadership: A Commonsense Approach
https://www.amazon.com/Small-Unit-Leadership-Commonsense-App...

The Five Dysfunctions of a Team: A Leadership Fable
https://www.amazon.com/dp/0787960756/?coliid=I12MQNI6MIK6JR&...

High Output Management
https://www.amazon.com/dp/0679762884/?coliid=I2G1Y1JLPP55SY&...

Measure What Matters
https://www.amazon.com/dp/0525536221/?coliid=I1G6EQRC0QYPE1&...

Death by Meeting
https://www.amazon.com/dp/0787968056/?coliid=I38A8AYMZGSLYZ&...

Work Rules!: Insights from Inside Google That Will Transform How You Live and Lead
https://www.amazon.com/gp/product/1455554790/ref=ppx_yo_dt_b...

The Hard Thing About Hard Things
https://www.amazon.com/Hard-Thing-About-Things-Building/dp/B...

Start with Why (you can prob skip the book and just watch https://www.ted.com/talks/simon_sinek_how_great_leaders_insp...)
https://www.amazon.com/dp/1591846447/?coliid=I2Q0IN84LJ230W&...

It really depends on what facet of business you think she'd be interested in.

To be honest I think better than any specific business resource out there would be to just get her on the path to building the core skills she'll use later on in life. She's already got that started with her vending business which is great. I think pushing her towards taking on some school activities may be great too. Things where she can help organize events and fundraisers and really contribute to a group.

As for my favorite books on business I would suggest for a 13 year old:

"Death by Meeting" The author describes a fictional company that is terrible at conducting meetings until the main character comes and helps address the issues. I know she's not really running meetings at the moment so this may be of less use to her until she has others working along side her. http://www.amazon.com/gp/product/0787968056

I also agree that "How to Win Friends and Influence People" is an excellent book. I grew up with social anxiety disorder and it was one of the books that really broke me out of my shell and gave me the confidence to really push past it. http://www.amazon.com/gp/product/0671723650

Another book I found pretty interesting was "Win the Crowd." While not a 'business' book, per se, it goes into how to really grab your audience's attention and hold it.
http://www.amazon.com/gp/product/0060742054

Lastly "Secrets of Powers Negotiating" is an interesting book I'd suggest she take a look at. There are endless applications to negotiation in business from sales to even negotiating your first salary.
http://www.amazon.com/Secrets-Power-Negotiating-15th-Anniver...

Just some ideas -- hope it helps!