Searchable database of Gaelic place names in Scotland. You can search under English or Gaelic name, postcode etc. and also view the place on a modern map.
http://www.gaelicplacenames.org/index.php
This site is a comprehensive modern gazetteer for Scotland which also includes entries from the Ordnance Gazetteer of Scotland 1882-1885. There are historical maps showing county boundaries and photographs.
http://www.scottish-places.info
Information on places in Scotland arranged by county or you can search the whole database. Results include maps, photographs, Ordnance Survey name books and medical officer reports from the 19th Century. These reports give useful background information on living conditions and diseases prevalent in particular parts of Scotland.
http://www.scotlandsplaces.gov.uk
This website has historical information on Scotland's counties and parishes taken from the Statistical Accounts of Scotland which were published in the 1790s and 1845. Subscriptions are available but some information can be accessed free of charge.
http://edina.ac.uk/statacc
This site has indexed entries in Phillimore marriages, Who Was Who, school and college registers and returns of owners of land from 1873. You can also browse the published parish registers of over 500 parishes in England with Lancashire having the best coverage.
http://www.uk-genealogy.org.uk/index.html
This site includes information on the history of Scotland as well as the Ordnance Gazetteer of Scotland 1892-6.
http://www.electricscotland.com