good resources are

the free bmd project at
"http://freebmd.rootsweb.com/cgi/search.pl"

which gives a lot of data on births marriages and deaths, but it is not complete, and a quick search did not give any results that were significant to me, you might fare better.

Another site that is more specific to your needs is the lancs bmd which is at
"http://www.lancashirebmd.org.uk"
when its good its brilliant, even prints the application forms for you, but again the data set is only partial.

Finally you might try the pay site 1837.com. I joined some time ago and it has been very worthwhile. For so much per page view (think it is 8p per view) you can look at the complete data set of births marriages and deaths for the whole of the UK since records began in 1837 (mainland data set only). Be warned though that the index is only partial so that it takes you to the first three letters of the surname, after that you have to search the images and it takes a great deal of time. At the end you only get possibilities in that you get the reference number in the registration book.

Marriages can be cross checked by looking up both surnames which should have the same reference number, then you will have to order the certificate from the PRO or local record office. I think that you can do this from the 1837 site direct, I have not used their service, preferring the direct approach, only report I have from a new cousin, is that they were slower and more expensive than the direct route but you mileage may vary.

Good luck