I have to echo what's already been said honestly.
I only get the toys that really appeal to me. (Comics and toys aren't really done to reflect each other.)
And since IDW has gone to an ongoing storyline, I find the comics are so stinking easy to keep track of... maybe the titles of the trades are getting you confused like "For All Mankind, International Incident, Revenge of the Decepticons... Chaos?" It's not like those titles explain 1-6, 7-12, 13-18, etc.
In which case, just ask anyone here on the forum... we can give you the short end of how it works and clear up any confusion.
The IDW collection is probably the easiest way to get everything collected in order, bound in a nice hardback, for the best price. Only thing is that you have to wait to get them. SO if you are patient its the best.
As for how things are arranged. Depends on what you have and what you last understood how things were working out? I'll just sum up everything since the Ongoing started beginning of 2010:
For All Mankind: (Ongoing issues 1-6)
Bumblebee: (mini series)
Last Stand of the Wreckers: (mini series)
International Incident: (Ongoing issues 7-12)
Ironhide: (mini series)
Revenge of the Decepticons: (Ongoing 13-18
Heart of Darkness: (mini series)
That's all the current trades. Everything else read on...
Ongoing 19- till 23 which comes out Weds... untitled yet.
We don't know what the lead up trade will be called? I'm guessing Prelude to Chaos? But until the trade is announced it could be anything?
Also there is the Spotlight Prowl which fits more in Ongoing 1-6 area. Still undetermined where that will be traded. And there are also two issues of Infestation. I believe that is in Infestation volume 1. If you are only interested in the Transformers section, try and find the two single issues because the trade will have the two of the other story which honestly doesn't really carry anything into the Transformers track. I'd say skip it but an important plot point sort of wrapped up in it. You might want to read it? (The whole Kup/Prowl thing.
Also, you could check out the Underbase podcast
... we review stuff weekly and have a news section at the beginning to point out things if you are interested. (Not that I'm trying to shamelessly promote the podcast, I do co-host it. ha ha ha!)