On organization and disorganization, writer’s style

Sometime back in May or June of this fast-ending year, I joined an online critique group for writers of (broadly) historical fiction. I did this to get feedback on my Invaders trilogy, but what I decided to do was revise the very first book – which, originally, was going to be the only book! So far, so good, and I've gotten lots of feedback, mostly pretty encouraging, but also areas where I could make the story or the characters more interesting, and certain suggestions from various quarters, on how I could do it. Again, so far so good. At the same time, I have been working on the third book of my trilogy, which wraps everything up into a more or less happy ending for most of the characters.

The problem with this is, that I sometimes have a hard time keeping track of what I'm doing, or what chapters I've been working on. So I sometimes have to go back and look to make sure each book that I'm working on is in its proper three-ring binder. Usually I don't have any trouble locating what I'm looking for, and I can tell at a glance whether it's the original draft – and everything is fine.

But today I was looking for Chapter 22 of The Melding. I found Chapter 21 and Chapter 23, but not 22! Fortunately, I did do a draft and then a revision of 22, and I'm going to put it away next Wednesday after I have my writing partner look at it, with comments, again. There it will sit, until I finish the first book, plus critiques from all over. I also plan to save all this stuff on a portable hard drive, just in case. I have lots of space on that, and that is one of the reasons I bought this external hard drive. Moral(if there is one): I'm going to have to figure out how to keep better track of my work, especially when I'm doing two things at once. Otherwise, I will be totally confused.
Anne G