There have been many excellent books written on Thames that are of interest to those with a history and genealogical interest. An old list that I assembled is available here. Also The Treasury has a list of just a few they have available and the Thames Library has a searchable catalogue.
Recently several people have asked about the availability of Downey's mining book on the Hauraki District. Reprints of this and several other books are available from Cadsonbury Publications. Downey's Gold Mines of the Hauraki District, Clarke: Thames Gold Fields Miner's Guide and Grainger's The Amazing Thames. The company can be contacted by email: cadsonbury (at) xtra.co.nz