The best info on the S&W revolvers is "The S&W Revolvers: A Shop Manual" by Jerry Kuhnhausen.
This covers about EVERYTHING known about the S&W double action revolvers, from disassembly, inspection of parts, reassembly, fitting new parts, to gunsmithing.
Price is about $30.00 from Brownell's, Midway USA, and can be ordered from most online and local book sellers.
No BS, there are a number of books around, but Kuhnhausen has more usable info than any of the others.