As a Shockwave fan,I'd like very much to read the story of his past in the original IDW approach,as a cheerful senator so different from his typical behaviour,and also as robot design.
It seems to me that his first appearance is in volume 2..(I plan to buy books on Amazon)then,which other books I should buy to completely continue all of his tale ,until then he changes ,and as a completely different character,he joins Decepticons?

Please no spoiler   ,I just want to know what are the books that include all of this tale.

 

The Transformers Volume 5: Chaos Theory contains the first story to feature him in this phase of his life, read the final two issues of that trade. It's only a small role but it's a very prominent role in order to see what he's doing at this time.
More than Meets the Eye Volume 3 contains the Shadowplay trilogy that depicts everything you need to know of his past.
Robots in Disguise Volume 5 recounts more of his past after the Shadowplay trilogy and his ultimate plan.
And finally, the twelve part Dark Cybertron event is what it all leads up to with Shockwave, however it would be best if you read all of MTMTE and RID to order to better understand and appreciate the rest of the characters and how they ended up in this moment. Also if you haven't read it, read Spotlight Shockwave, that is the ultimate prelude to everything that leads up to Dark Cybertron.

Is it possible to retitle this thread though to "MTMTE volume that feature the Senator"? It's just someone else on this board is reading through all of the IDW comics at the moment and he's a long way from this plot twist and we don't want anything spoiled for him when he sees the title and goes: "Shockwave was a senator? Whaaaaaat? I've got to look out for that. It's probably that suspicious guy there." Don't worry if you can't retitle it though he probably won't pay too much attention to it, just checking. Happy reading!