Don't ever scan straight to PDF. Always scan as images, process them, and
then pack them in a PDF, if you want. The way I see it, you can export the PDF as images using one of the many virtual printer drivers on the net, then run the images through Scan Tailor.
FineReader will import the PDF as images and process them more or less similar to Scan Tailor, except with OCR. I don't like doing this because it basically takes a screenshot of each page from the PDF and loses resolution.
There are two options:
1. The "quick and dirty" way, using Scan Tailor + FineReader. Images on top, positional OCR underneath the images. The text won't reflow, but at least it's searchable (within a ~95% margin, if you don't proofread it). You won't have to worry about fonts or the layout, but you also won't be able to easily correct typos or other mistakes from the book, since they're just images.
2. The "quality way", using FineReader to extract the text, proofread it in FineReader, track down the fonts, process the graphics, redo the layout, proofread the final product again. Takes a lot of time and effort, not many people stick with it... but believe me, it's always a pleasure to read such a book. Make sure that the material is worth it and that it's not already available as an e-book. Training videos on how to use InDesign, Word, Acrobat, etc., can be very helpful.