I've been trying to find my way around in the familysearch site by using the T&E method (trial and error

) and seem to get better at it. What puzzles me though is when I have positively identified the birth of a female and then want to look up her marriage date and husband, I never know whether to use her maiden name or not.
Are the marriages registered for a woman under her new name or her maiden name?
If Miss Jane Smith married a Joe Soap, do I look for Jane Soap or Jane Smith to find her marriage registration?
2nd question; if there is just a reference to a marriage in the above case (no husband's name, no mother's maiden name etc), would I get further details from the original record? It does not seem to make sense when a marriage is indexed but the spouse is not listed.
3rd question; when a mother's name is listed in a birth registration, it is sometimes a double name, one of the father & husband, the other one is - I assume - her maiden name. Is there an order in the indexing of these double names? \His name first and then hers or vice versa?
Maria B