2 websites to see old maps.
National Library of Scotland
https://maps.nls.ukThis has old and modern maps. You can put them side by side.
Lancashire County Council - Old Maps
www3.lancashire.gov.uk/environment/oldmap
You can search for photos of places in recent times on this site:
geograph photograph every grid square
https://www.geograph.org.ukGENUKI UK and Ireland Genealogy compiles information about places useful for family historians such as lists of churches and cemeteries with dates of operation and location of records. Interactive map e.g. can ask it to show location of churches of a specified denomination. Pages for Great Harwood are at
https://www.genuki.org.uk/big/eng/LAN/GreatHarwoodYou need to enlarge the map to see where Haslingden is in relation to Great Harwood. It's missing from the normal size map although Rawtenstall is on.
Can click on a link to a Great Harwood website from GENUKI GH page. If that doesn't work it's at
www.great-harwood.org.ukBtw be careful not to mix up Great Harwood with Harwood near Bolton. Google has. There is a reminiscence site which appears as Great Harwood but it's actually Harwood near Bolton.
Lancashire Archives catalogue is online.
Lancashire Family History & Heraldry Society has branches in both your areas of interest. One of the societies 2 research centres is at Oswaldtwistle, which is not far from Great Harwood and Haslingden. The society has a website and an online forum.
See RootsChat Lancashire Resources on Lancashire County board for more suggestions.