There are many sites websites that give useful information on civil registration records as well as parish records. The most comprehensive site is operated by the Church of Latter Day Saints based in Salt Lake City. The URL is:
http://www.familysearch.org
There you will find the International Genealogical Index, Census data for England, Wales, Canada and the US, and many other items of interest.
The LDS library itself in Salt Lake City has a huge collection of material from throughout the world.

http://freebmd.rootsweb.com
will take you to a site which contains the results of a major volunteer effort to put online the Civil Registration records of births, marriages, and deaths for England and Wales from 1837 to, currently, 1906. There are about 60 million entries thus far with many more to go. The complete set of records on paper can be found at the Family Records Centre in London.

The 1901 census for England and Wales is available on line at
http://www.pro.gov.uk/online/census.htm
Fees are charged at this site for copies of census entries.

To find the most comprehensive LIST of sites go to:
www.cyndislist.com
This site, created and maintained by Cyndi Howells, provides links to more than 188,000 other sites of interest to genealogists the world over.