Once you've exhausted other avenues, these records may help to give you a picture of your ancestors lives.
Central Library holds a large collection of school records for the Manchester area. Surviving admission registers c.1870-c.1916 for Manchester schools are available on-line on findmypast.co.uk
Admission registers are compiled at the time of a child's admission to a school. They record a pupil's name, date of birth, address, date of admission and leaving. Often also included is a parent's name and standard reached before leaving.
Ancestry.co.uk has a good collection of military records including the medal index cards.
Local newspapers can be useful for searching for notices of:
The library has a good collection of maps of Manchester and the surrounding area, showing the development of the city from Roman times right up to the present day. Maps can be used to examine the area in which your ancestors lived. Many of these maps are now available on-line.