Yes, IAE is the time to try and figure out a CCU chain. How it works is you keep track of the missing pieces (that is, the gaps in your chain) and buy CCUs that might fit those gaps.
One thing to keep in mind is that you can either aggressively buy every CCU that may lead to a better CCU chain, this way you'll end up having the most efficient possible chain(s) but also plenty of alternatives so if you're only going for a single chain, it's not quite as effective overall. If you're going for multiple CCU chains, then that's a pretty solid stance, and in the end you'll need some store credits to fill in the gaps anyhow. Alternatively, if you just want a solid single CCU chain, you'll just have to roll the dice on the CCUs and hope for the best without getting any alternatives. It might not lead to the most awesome single CCU chain, but overall you'll be spending less as you're not creating a sprawling CCU empire and ending up buying more ships than you initially planned. There's pro's and con's on both approaches. Just ask me to clarify if the explanation wasn't confusing enough.
During IAE there are a couple new offers each day, so you need to check daily. For historical data on what the event might look like, we've been keeping track here:
https://testsquadron.com/threads/ilw-2954-wb-ccu-watch.21205/ (open the spoiler for previous years to see how the event has evolved). There'll be a new thread this year as well, unless some sort of new family addition is keeping me too busy.
I've used CCUgame in the past, many still do, but I reverted back to using spreadsheets. I felt like that gave me a better overview, but that depends on how strong your spreadsheet magic is.
Oh, and keep in mind it's not just the CCUs you're after, but also some concept ships for store credits if you've got some. In case you're going after a $600+ ship, pay particular attention to the very old concepts still valued at $350, like the crucible and endeavor. Those still have a massive potential to go up in price. Hull B might have some fuel left as well, though it already went up by $50 on a very low starting point. And keep in mind the Endeavor will only be released sometime after 1.0, so it might take a very long time for that benefit to materialize.
EDIT: Oh, I actually linked ILW from this year, but the link to the IAE from last year is there, just follow it. I'll keep the ILW linked since you'll have the benefit of checking the most recent event, though ILW is always a bit smaller.