Marketing to library's

I've previously written two books published by professional publishers who've done all the marketing. I've just produced an e-book which is now being printed (self-published) as a hard cover resource manual (on filing disability claims w/insurance companies, Social Security and the Veterans Administration). It should be a perfect topic for marketing to libraries as 1.) It's unique as there's nothing else like it in print 2.) There's almost 2 million Social Security disability claims denied each year so the problem is serious and getting worse and 3.) Disabled people can't afford to buy books so taking it out of their local library should be an option for them.

I've submitted my publication to Booklist but it remains to be seen whether they'll review it as they only review one out of ten submitted. I read about firms that market exclusively to libraries but 50 to 60% commission seems a bit much and I'm gunshy about who to trust.

We're just submitting to the search engines and we need to start a full blown campaign. I see there's a Book Expo coming up on 10/22 but I'm not sure if that'll be a good source of guidance.

Has anyone been in a similar spot who wishes to offer some guidance?