What are some good ways to prepare for Ranger School

I'll echo what others have said, run/land nav/ruck march/etc. But the biggest thing you need to prepare is your mind. There is nothing overly hard about Ranger School physically speaking. It's exhausting, don't get me wrong. But no one is going to ask you to run 20 miles in 20 minutes. It's the mental wear and tear that gets most. It sucks. It sucks really bad. Prepare yourself for that. You are going to get little food and less sleep. You will be wet. You will be more tired and hungrier than you've ever been before. Just embrace the suck and DO YOUR JOB when others are in leadership positions. If you do that, they'll take care of you when you're in leadership.

The other thing to know is that Ranger School can be like the Wheel of Fortune. How you do depends greatly on who's evaluating you. I was there for 4 months and failed to graduate. I hate that, I really do. But it just wasn't meant to be. I gave it all I had and it is by and far the best military school I've ever been to. You will learn more about yourself and about leading others in your time there than in any other training environment. So just give it your best and don't leave until they make you leave.

Good luck!

You are the third person I've head about getting sent Infantry as branch detail when it wasn't on the list. In Italy, I met a 2LT in your shoes, AG but detailed IN. I just met a 2LT that wanted Signal Corps/Cyber, and he was programmed IN. Odd. First, don't worry about Ranger School. You need to be prepared for IBOLC. IBOLC will give you the tools necessary to get through Ranger School, more so that than be a Platoon Leader in an IBCT (you'll be deficient is personnel, maintenance, supply readiness...but a "go" in training since that's what IBOLC focuses on). IBOLC's six month physical training program, Land Nav week, and multiple Patrolling weeks will get you through RAP week. The only way you are ousted from RAP week is if you don't take advantage of IBOLC's design to prepare. Do complete push ups, understand your land navigation techniques, be road march within the time alotted. Once you get through RAP week, the probability skyrockets for completion of the course. In addition, being a good dude, team player, and positive will also earn you a good reputation within your squad/platoon.

Catch up on running and rucksack marches, hydrate, and try to put on a few extra pounds before you report but stay well under the max. Your body will need the calories eventually. Also find a Ranger handbook and read ahead.