Reddit mentions of Wood & Beer: A Brewer's Guide

Halfway through the new Wood and Beer book from Cantwell and Bouckaert. So far it reminds me of the elements series. Lots of interesting first hand accounts on how barrels are made, as well as their history, etc. Less dense on the practicalities of working with barrels. Could have used another pass by the editors, lent my copy to my friend Nathan Zeender... they misspelled his name (they have a couple mentions of Chad Jakobson of Crooked Stave as well...).

I've mostly moved away from barrels and back to cubes over the years. Big barrels are too much all-your-eggs-in-one basket for me (better to have 12 carboys with 12 different cultures). Little barrels are fun, but you get so much character so quickly, it is a struggle to keep up with demands of refilling.

As a side note, I'll be doing full-day classes on wood-aging and sour beer in Burlington in early November as part of the BYO Boot Camp series (more locations to come if this is a success).

This should set you on the right track:

https://www.amazon.com/Wood-Beer-Brewers-Dick-Cantwell/dp/1938469216/ref=sr_1_1?ie=UTF8&qid=1517603568&sr=8-1&keywords=wood+and+beer

I can't help you and I'm not being an asshole but I've been casually reading this book

You're answer will probably come as we have plenty of experts here. I highly reccomend that book if you're interested though. There's a TON of "how to" style walk-throughs in it.

https://www.amazon.com/Wood-Beer-Brewers-Dick-Cantwell/dp/1938469216

There are a lot of variables involved, and they're going to impact how you do different things like sanitization, how long you age, how long before your barrel approaches neutral, etc. For example, a new barrel versus a freshly emptied spirits barrel versus a previously used barrel that was dumped 6 months ago; they're going to have different sanitizing needs. I'd recommend taking a look at the book, Wood & Beer, https://www.amazon.com/Wood-Beer-Brewers-Dick-Cantwell/dp/1938469216. Lots of really good info there.

Personally, I wouldn't consider anything smaller than 5 gallons, but 10 is probably better (assuming you can do at least 5 gallon batches). The reason is most styles that do well in barrels also will age well, so if you're going to put the work into it, you might a well get a decent amount out of it so that you can cellar some of it Volume to surface ratio also comes into play as does stave thickness on smaller barrels.

As for sources, small batch distilleries are a good source. If you're in the US, homebrewfinds.com often has posts when barrels become available from various suppliers.