There are many excellent databases to use when you do your history research. The following are great places to start:
Remember that you can't use ordinary language sentences in databases! You have to combine search terms with AND or OR.
Most databases provide some kind of wildcard or truncation used for terms that you put in the searchbox. This may be an asterisk (*), a question mark (?), or a colon (:). Truncation allows you to find variations of a word, like the plural.
For example, wom* will find you records in the database for woman and women. Unfortunately wombat too! Truncation can sometimes pick up records you may not want to see but you can just ignore those.
Databases also often let you limit your search by other elements such as language, date and format. You can use parentheses to group ideas or common phrases e.g. "war of 1812".
Be cautious about using limiters though. In your first try at searching a database it's a good idea to do a broad search first just to find out what the database has on your topic. If you use limiters right away you may lose some records you want to see. You can always limit the same search by trying it again; the search will be narrowed down. This is especially true for the databases Historical Abstracts (European history) and America History and Life (American and Canadian History)
You may need to search a topic several times using different terms to find all you need for your assignment. Try different search words with similar or the same meaning (synonyms). It's not usual to try several searches in different ways to locate the articles you want. Keep trying!