Yes, there are lies on marriage certificates.
Some useful links:
BMD Certificate Tutorials:
http://home.clara.net/dixons/Certificates/indexbd.htmResearching From Abroad:
http://www.genuki.org.uk/ab/See the Board Information link on the England/Feneral message board for more links.
Parish registers, even after 1837, the start of civil registration, are wonderful sources of information. See GENUKI
http://www.genuki.org.uk for links to the county in which your ancestors lived. Go to that county page and information about parish registers can be found. If you're fortunate, there may be an Online Parish Clerks project for the county. FamilySearch.org has some parish registers online and some on film, copies of which can be rented through your local Latter Day Saints family research library.
For more local information, post on the appropriate county board and include specifics about your ancestors (names, dates, etc.) To determine which is the appropriate county board, put the name of the town, hamlet, city, etc., into GENUKI's Gazetteer
http://www.genuki.org.uk/cgi-bin/gaz It's also very useful to subscribe to and post to the surname list that matches your ancestor's name as well as the location list. See
http://lists.rootsweb.ancestry.com/ and
http://lists.rootsweb.ancestry.com/index/index.html to find mailing lists.
Hope those links get you started.