Which book would you recommended as help (assistance) for reading the so-called "Tohoku Paper"? Recently I thought that maybe is a good time to try, read Grothendieck's "Tohoku paper" as a sort of inspiration for the future and to read some of the ideas of this great mathematician, which (among many of course) indisputably is one of the most inspired papers in contemporary algebra (and not only). However, because the subject is quite difficult even for experts I was thinking that maybe a book would be necessery for definitions, comments or even examples on some of the notions that this paper includes. Also, I found a translated from French to English version (by Michael Barr) and I think that is the only one that exists. Is this version the "official" or there are others?
Also, do you know if there is any book that might help me on that? Or any other papers towards that direction, that might be helpful as well?
 A: As far as I know, there is no other translation.  However, you should know that there were two translators, the other being Marcia L. Barr.  She is a professional French/English translator and I put it into mathematicese.  Very much against G's wishes; otherwise it would have appeared as TAC reprint.
As for your question, in 1957 category theory wasn't even a thing.  I suppose Godement's book is as good a place to begin as any. I would also recommend Cartan-Eilenberg.  The Tohoku paper and Dan Kan's discovery of adjoints are what put CT on the map.
A: There is at present a renaissance for the work of Alexandre Grothendiek. Seems that his posthume reputation has grown a lot. For the simple translation it is sufficient to read the answer from Michael Barr. There is very interesting review from Rick Jardine on tohoku. Rick Jardine points out the very importance of the different achievements by Alexandre Grothendieck in his tohoku publication on different innovative branches of modern mathematics. He makes clear that this is through the work that is the initialization of so many important works, conjectures and nowadays valued new fields of mathematics.
Rick Jardine makes some introductory remarks on various chapters and names flaws by Alexandre and groups and mathematician that were competitors to Grothendieck or successors and founders of math innovation that did deviate from the standpoints and perspective in tohoku. Thereby he allows and induces thoughts accessible and required on various level of modern math education.
There is a vast collection of linked resources with the text. I recommend to work with wikipedia.org definition to work on the publication and the review in coherently and easy manner.
There is another article tohoku on nLab offering some fresh links on the looked for translation of interest and some other modern resources that allow to think different about the original revolutionary, relevating publication.
My opinion is the the plain attempt to read and understand the tohoku text is a waste of time. The text should be reviewed in the manner that Rick Jardine does it. The text is a map through the topic in Homological Algebra with deep impacts in many different topics in mathematics. To the read the referenced texts offers not only a deeper comprehension but is a island for mathematical literacy as well. This is inspired by the high literacies of all authors.
