This one is the official main story : http://www.mangago.zone/read-manga/shingeki_no_kyojin/ it's pretty much the only important one.
And this one is about the past of Levi (a character you'll meet in the main story) http://www.mangago.zone/read-manga/shingeki_no_kyojin_gaiden_kuinaki_sentaku/ it's a nice read if you like him.
Thank you! So very much thank you!
you can also find them all at barnes and noble. I actually read the novel of before the fall which was about Angel, the inventor of the maneuver gear and I even got vol 4 and 5 of this one.
No that's not right. This is before Levi and Erwin were involved at all in the SC. This is a story about how the 3-d maneuver gear was created. Also about the "titan's child" Kuklo and Sharle (a noble's daughter). This is about when Humanity within the walls begins to have hope that they can fight against the titans.
If anyone could help me with these Attack on Titan series I would really appreciate! Where do I start reading?!! I'd like to start reading the story properly but can't seem to find the original! There are a lot of yaoi doujinshi out there and are somehow blocking me, or flooding my searches, from finding the original story. Someone please help!