For the best references just read the wiki or the "-tions" stories they are at best vaguely referenced to. this includes maximum dinobots. Same for Autocracy and Megatron Origins. You can do the same for the Bumblebee and Ironhide minis as well.

If you can get them on sale via comixology or borrow them, read all hail Megatron and the first 5 trades of the Costa led ongoing. They are not worth paying for.

Read or purchase chaos theory and police action as they most directly precede 125- death of Optimus Prime. Last stand of the Wreckers is not massively important but is an excellent comic series by a similar creative team.

As for the spotlights from the Furman era, some are very important to the current stories, others worthless. You may want to read: Shockwave, Hotrod, Wheelie, Nightbeat, Arcee, Hardhead, Cyclonus, Optimus Prime (not to be confused with Orion Pax). I could recommend another half dozen spotlights, but those are the ones that jump most readily to mind regarding current stories, especially Arcee, Shockwave and Wheelie.

Happy reading.