This book "... is an ideal reference source for learners and users of Slovene at every level: independent learners, university and college students, and professional linguists."That's what it says on the back cover.
Slovene in unlikely to be a language you will try to learn on a whim, but if you have a love for the country, as I do, then you may wish to develop you Slovene skills. But if you are an independent learner, you will find this book certainly comprehensive, and MOST certainly difficult.
I advise you use it in tandem with something much more accessible.
One cannot criticise the content of Mr. Herrity's tome, but consider this...
Do you know your obstruents from you sonorants?
Or that the letter "v" is can be pronounced as a voiceless bilabial approximant?
Are you familiar with jotation?
Or pluralia tantum nouns?
Or bound clitics?
I could go on, but you see my point.
As someone learning Russian, I already understand some of the complexities of learning a Slavic language for English speakers... I'm afraid Mr. Herrity's style does not make things easier. (Unlike Derek Offord's Advanced Russian Grammar).
But see it through and you (and I) are sure to be rewarded, as there is everything you are ever likely to need to know...
...and MUCH more!