A very useful Dictionary of Occupational Terms was available on CD from the Open University. Some copies may still be available through the Family and Community Historical Research SocietyFACHRS) or you may find a it among your local FH Society's resources. This CD reproduces the 1927 Ministry of Labour guide to occupational terms used in the 1921 census. Although this is a 20th century publication, many of the terms are unchanged from their 19th century usage.
The Clergy of the Church of England Database (CCEd) - http://theclergydatabase.org.uk/ - is a collaborative project to create a relational database documenting the careers of all Church of England clergymen between 1540 and 1835.