I've just started a new website about Liverpool's history, covering the period 1770 to 1870. - http://www.leverpoole.co.uk/
Currently online: Liverpool's first history book, written by William Enfield and published in 1773. This contains a map of the area around Liverpool drawn up in 1768, and views of public buildings including the infirmary, churches etc.
I've attached a section of the map, covering the city centre.
Herdmans Pictorial Relics, published in 1856.
Fisher's Lancashire Illustrated, published in 1830.
List of Liverpool streets in 1871.