I medically retired, very unexpectedly, after 12.5 years, so I didn't have a year or more to prepare. The transition is brutal, unless you move directly into an S3/XO job at a defense contractor doing the same thing you were doing in a different uniform.
One of the biggest challenges I think people have when retiring is salary expectations. Wherever you go, you'll be a newbie. Most people I know left the Army expecting $100-$120k jobs because "that's what I've been earning." Those jobs for people coming in with no experience are really, really hard to find. You should be realistic when weighing your skills to the market. Remember, just like in the Army, there are hundreds of people out there just as good as you after the same job, so if you ask for $30k more than they're willing to offer, they're going to go to the next candidate.
A lot is made of "leadership experience" gained in the Army. Does it matter? Of course. Is it what matters most? Probably not, depending on what industry you want to get into. I had a lot of good stories to tell in my interviews about "tell me about a time you had to correct a subordinate's performance" and "tell me about a time you had to make decisions that were not popular but were important to the organization", but those aren't what got me into the interview. Hard skills matter. Math, Excel (not the S3 shop's tracker, macros and pivot tables etc), Minitab, SQL, R, statistics, VBA, Primavera P6, MS Project, regressions, etc. Those are the skills that business-world employers need you to have so that they can concentrate on teaching you the specifics of their company. MrExcel makes amazing books and YouTube videos. Hector Guerrero's book "Excel Data Analysis" is awesome. Oracle has YouTube videos of SQL and P6 for free. Udacity.com offers free online mini-classes (taught by geniuses like Sebastian Thrun and Zvi Galil) for almost all of those. Being able to talk the talk is important in an interview.
Don't get frustrated with the pace of the hiring process. Nobody in the civilian world moves as quickly as they do in the Army. I had a dozen interviews where I was told "yes, you're exactly what we want!" only to never get another phone call - and I have plenty of hard skills for the ol' resume. Recruiters won't be honest with you about what the company is doing. Polaris bought me a plane ticket to go to Huntsville, AL for a third interview... when I got there they told me a plant in Iowa was closing and all the Alabama hires would come from there. When I finally signed an offer sheet here at my current job it still took 2 months before my first day.
Paying a professional to write your resume is a worthwhile $50 investment. Have them make 3-4 different versions. Tailor the wording every time you submit it somewhere - don't have one single canned copy.
"Military Friendly" boasts by employers is as meaningful as a yellow ribbon magnet on a car. Do they like you? Do they value your drive, competence, aggressiveness, and sense of duty? Yes to all. Are the hiring process or the job expectations going to be any different than everyone else? No. Nod politely when they say that but don't expect it to mean much when it gets down to brass tacks.
