Best practical readings to prepare for a career in FDD

I work in FDD currently. I wouldn't worry too much about reading beforehand. If you must, just pick up "Investment Banking" by Rosenbaum/Pearl or any other book that explains the deal cycle. This will help you better understand how FDD fits in. The bigger things to worry about are:

1. Excel skills. At the lower rungs of FDD, your job is to take really shitty data and transform it into IS/BS, breakout tables of key FSLIs (i.e. revenue, COGS, etc.), and potentially ad-hoc analysis (i.e. top customers, analytics concerning realization of AR, etc.). This means you need to be VERY comfortable with INDEX(MATCH), SUMIFS, Logical Functions, and PivotTables, Charts as table stakes. You'll also probably learn Tableau/PowerPivot at some point. You'll pick some of this up as you get reps on deals and by looking at old report. The more front-end work you can do in excel, the better off you'll be.

2. Writing skills. Work on being concise and stating what's important in as few words as possible. A lot of ex-auditors are used to writing for the sake of writing or using flowery language to try to convince the PCAOB that an obvious fuck up by the audit client is not an exception and requires no further testing. This is a bad habit. Get used to the idea that it's often better to leave white space in a page than it is to fill it up with superfluous words. If white space really makes you cringe, put in an analytic/graph to highlight your point instead of saying it in words. If that still doesn't work, consider whether you're spending too much time worrying about something that doesn't matter or if you require more information because you only have 2 sentences on a huge business risk.

3. Mentally prepare yourself that there will be sink or swim moments where you don't know what question to ask and the people above you may not have the answers either. This is something that people at all levels struggle with to some extent, but what inevitably separates good consultants from bad ones are people who can think outside of the box and come up with solutions from ambiguous/incomplete data. You're no longer in audit where you can rely on PY workpapers on the same exact client with minimal changes. Each deal is different and you'll eventually start to figure out what's important and what's not after 4-6 deals.

Hope this helps!