Recommend listing women by their maiden name only, if known. If not known, then temporarily use the husband's surname in quote marks to place her with the appropriate family connection. This will help avoid confusion should one accumulate the names of several women with the same given name, but no known maiden name, and the need to determine which husband each should be connected with arises.
In a search inquiry, the maiden name may provide results about the woman prior to her marriage. Using the married name may provide results after marriage, but may also provide results of other persons whose maiden name or married name is similar to or matches hers.
Choosing to use her maiden and married names together in the surname field may skew the search results and one could miss out on applicable hits that do not contain both surnames.
I hope this information is helpful to you in getting started. Once your tree begins to branch out a bit, you will be interested in collecting the census records and vital records for your ancestors. Another good site is www.familysearch.org
where one can find digital images of vital records or older courthouse register pages for births, marriages, and deaths. Generally, actual death certificates may be found from c.1908 to c.1953 for some states, but each state is different.
Genealogy can seem overwhelming in the beginning; but if one takes small steps at first, one grows more confident and can move into other areas of research. The Ancestry.com (ACOM) card catalog can be very helpful in finding new databases to search. Here is the link: http://www.ancestry.com/search/rectype/alldblist.aspx
Documenting or sourcing events before placing those in one's tree will save a lot of work later if one can then link those documents to one's tree. Save all vital records directly to your hard drive for permanence.
The Learning Center tab in the above toolbar may be helpful. Reading these Message Boards can be an invaluable source of information. Mary Beth has offered to provide one on one assistance. Don't hesitate to ask questions as someone will usually see your request and volunteer additional assistance.
Best wishes on your success.