No, you do not need books.
What you first need to do is get scans of each of these stamps, individually. The scans ought to be at 800dpi.
Then go to this website https://www.spink.com/nissen-reconstructions.aspx
and look up the images for each of the letter combinations you have and find the best match with regard to the placement of each of the check letters within each of the lower corner boxes. That is, high, low, towards the left, towards the right placement, if a letter is slanted or otherwise aligned.
After you have the best match, if you care to, post the image of your stamp and your view as to the plate and I and others would be happy to look at it and give you feedback.
You do not need to buy any books and invest in any thing other than a scanner.
If you are really lost, then just post the image of your stamp, again scanned and not photographed and you will probably get feedback. (The reason a scan is needed, is that you are looking for small issues wrt check letter alignment and photographs are not from a flat plane and introduce too many mis-alignments and make the process too difficult and prone to error.)