How do I best prepare for an assignment as a First Sergeant? What is your best advice?

1) Start learning college writing if you haven't already.
2) Learn how to properly complete the Unit Commanders Financial Report
3) learn how to use both the Commanders Portal and MEDPRO's.
4) Learn how to use DTMS if you dont know already.
5) Learn TAMIS if you dont already
6) Reread AR 670-1
7) Reread your local Blue Book if one exists
8) Read the official guides to counseling again. Once you've done that, do it again.
9) reread AR 600-8-22.
10) Reread the APRT FM, and familiarize yourself with the latest on the ACFT
11) Take courses on Word, PowerPoint and Excel if you haven't already.
12) Reread AR 600-20.
13) Make friends with your legal advisors
14) make friends with your local IG.
15) Make friends with the chaplain
16) make friends with ACS and the Red Cross. They can help our Soldiers a LOT.
17) make friends with the XO's, both Company and BN. One will rely on you for guidance, the other is a great ally to have in your corner.
18) know how to do monthly AAA reports correctly.
19) know your METL and its associated tasks and sub tasks. This should be the lynchpin of your training plan
Finally...
20) Some friendly advice from someone who just did it for two years. This is the same advice that was given to me, and that I passed on to my relief..
There will be days where you feel like you're drowning. There will be days where you feel like you're failing at everything. This is perfectly normal. You likely aren't failing. You CAN breathe, and you CAN do this. I can't tell you how many nights my Commmander and I worked till 21, 2200, or how many times we shut the door and shared a mutual emotional breakdown, put ourselves back together, and went out to get back at it. There will never be enough hours in the day. You will never accomplish every single task. There will always be more tasks and more missions. Today's #1 priority is often tomorrows forgotten task while pursuing the NEW #1 priority.
You are the eye at the center of the hurricane. This is controlled chaos. Enjoy it, because it will be over before you know it, and you'll miss it.

Man, just be yourself- don't assume airs, remember to balance between being the Co's hatchet man/eyes and ears and the mentors for your younger NCO's. Hold off to make empire changes till you see the lay of the land for yourself. In essence you are just going from 40 to 120+ folks.

I’ll weigh in as having billets with 1SGT equivalents and as Skipper with CSM (CMC for me). What’s missing is getting an early read on how the Capital C Command Skipper and the CSM run things. Get in early with the CSM. There will be senior NCO coffee clutches. Go to them. Good CSM types will introduce you around quickly. You’ll get filled in on what the Skipper’s hot and cold buttons are. That way you can help keep your CC on a good track. You have a tremendous load taking care of your people. A good CC will unleash you to do what great NCOs do best. Also, part of your job is to make the overall command run well. Keep an eye out with the other sections (companies, S-1, etc.). Help them do well. Become “known” in the good way. You’ll be extremely visible to the big Skipper and the CSM. They both will assess your effectiveness and potential for future CSM. It’s a real bottleneck moving up at this stage. Just focus on your job, your people, and the overall health of the Command. It’s easy to sort real doers from the rank chasers. The later didn’t last long in my Commands.