What do you keep in your Platoon Sergeant Leaders Book?

This is what I would suggest - you want the things that will be asked for, and the things you will want to know. Ignore those fancy "baseball cards" and other nonsense that people make for presenting their leadership books for inspections. Your leadership book needs to be the things you will need to look up quickly, but exempt any PII or other protected information.

The things you'll want will be an ERB, a very very basic personal data sheet with DODI, SSN, family and family birthdays, anniversary, current home address, and permanent profiles. You'll use this for writing awards, NCOER's, and (hopefully) giving Soldiers the day off for anniversaries and birthdays.

The things you'll be asked for that you will want to have in your leader book are schools attended, blood type (not all are on the SRB), blood type (completely worthless because the CSH will retype them if they need blood), battle roster numbers, MIL drivers license numbers, mask sizes, uniform sizes, boot sizes, hat sizes, spouse or emergency POC.

All that is hard data and that's what should go in hard format of a PSG leader book. But you have moving data as well and that should go onto an Excel spreadsheet tracker. Things you want to track on excel are weapons serials, optics serials, mask serials, really any serial for any property whatsoever, DLC dates, NCOER thru dates, PCS dates, YMAV dates, DEROS dates, ETS dates, DOR/TIG dates for promotion, anything related to promotion eligibility, an entire separate tab for MEDPROS/PRR/Admin readiness (including cyber awareness, and whatever additional classes your unit requires), PT/weapons/ACFT scores and dates.

Things not to have - Don't keep SSN's in a leader book you carry with you, it's too much PII. You are not allowed to request previous NCOER's from your Soldier, that is protected by regulation. Don't ask for previous GOMORs, Article 15s, or anything protected under Unfavorable Information. Don't ask for spouse emails they will already by bombarded by FRG. Don't use some old personnel data sheet that asks too much info, make your own that only asks what you need; some of those have crazy info that you don't need or shouldn't be on a sheet of paper that is left around like mothers maiden name or Soldier location of birth.

Not a PSG but have been in a similar role many times. For each Soldier:
DOD ID#
DOR/Eval due dates
Blood type
Next NCOES
DL atatus for grade


I also keep my 50m targets and 100m targets tracked on there as well as my sections OML for schools.

This is the worst possible answer you can hear, but.... It depends on you and on your unit.

What are the Commander's (and 1SG's) priorities? If they are SERIOUS about monthly counseling, it would be good to have a record of the last time each Soldier was counseled. If they are big on PT, maybe a copy of their last scorecard, or at least a break down of raw/calculated scores. Etc.

Either way, you are going to want a data sheet on each Soldier. I loved to have mine in document protectors with non-changing data (name, SSN, DOB, etc.) typed on the actual paper, and changing data (last counseling, PT data, etc.) written in alcohol marker on the document protector. I also recommend a free form area at the bottom for "pending issues" where you can note the most important things you need to be tracking / running down for that Soldier: Pay issues, promotion, UCMJ, missing equipment, profiles MOS qualification, whatever.
IN FRONT of that data sheet, you want a consent document from each Soldier saying they consent to you keeping their information in your book.
Behind that data sheet, supporting documents (PT Card, weapons card, language test for FLPP, whatever is important for your specific platoon in your specific unit).

I was also a big fan of tabbed dividers. Label the tabs, and you can quickly navigate your book to each Soldier.

Beyond the individual Soldier data, I also recommend Company METL / Platoon Collective Tasks that support that METL, the current assessment (T/P/U) of those tasks, and the training plan to support those collective tasks. Depending on the unit, having the Company weekly training schedule may also be exceptionally helpful. Also have AT LEAST one Task/Condition/Standard for a hip-pocket training to take advantage of unplanned white space / standing-around-doing-nothing time.

Ultimately, the Leader's Book is YOUR tool, so you put in it what will help you do your job. As time goes on, you will realize more and more that there simply is not enough time in the day/week/month/year to accomplish all of the required training. So having a book that allows you to maximize training time and minimize "dead time" will help you and your Platoon stand out from the pack. Your Soldiers may curse your name behind your back because you drive them hard, but they will also talk shit to every other platoon, because they know they have gone above and beyond what everyone else is doing.

(That being said, take care of your troops, and give them time off when you can. Work hard, play hard. If you don't have to be at work, don't. But if you have to be there, be productive!)