From Web to Book

Hi!  My name is Pete Porter.  I have published a book of poems cal;led "Suggestion Schemes and Other Things" that is available on Amazon, both as a paperback and in a Kindle version.  This was produced  via BookSurge and has an ISBN of 1-4392-0463-2.  However, since publishing this item I have also found that I can produce my own books by creating them in pdf from pages that I have previously produced on some of my Web Sites.  One of these is an illustrated Autobiography of my father’s career in the Royal Air Force.  This includes sections on his pre-RAF life as well as details of his time in the Great Escape Camp, Stalagluft III.  (Although this is in his own words, I was able to transfer his verbal account to an html version that is currently accessible at   I was also able to print this on double-sided 5×8 pages and get the finished 220 page compilation bound at OfficeMax for less than $4.00.  I have already sold several copies of this item for $20.00 but would like to get it registered with an official ISBN before I go any further.  ""  looks like it may have a solution to this requirement.  Please let me know how to go about it.