here are a few things i have either wrote or rebloged over the past month or so. you will find them very helpfull
https://steemit.com/steemit/@louisthomas/226w4x3i
https://steemit.com/steem/@doomsdaychassis/gearing-up-for-filing-taxes-in-2018
https://steemit.com/bitcon/@the-bitcoin-dood/an-afternoon-at-the-accountants-crypto-taxes
read all 3 and you should be pretty good to go on where and how to gather the required info as painlessly as possible. hope this helps
sorry for the self upvote but i was trying to get this where it can be seen for the information contained.