SocINDEX is the primary research database for Sociology researchers and includes citations and abstracts for over 3,000 journals. This means that it is the most comprehensive place to look for an article for sociology, but that you should not limit it to the full text - you're likely going to be able to access the full text somehow!
Located under "Subject Terms" (the third link in the top menu), the thesaurus will help you identify the best term for your search as well as allow you to search for resources tagged with that term. There is a significant difference between the results when you search as a keyword and when using the subject term.
You've likely used or seen them used before, and while you don't need to know too much on the technical end, there are some that will help your search:
The asterisk extends the word, in that it will search for every word in the database that starts with the letters you typed before the asterisk. Be careful and thoughtful when using, since if you don't give enough of the word you can find a lot of unrelated words.
Putting two or more words in quotes groups those words together as an exact phrase, which will give more relevant results if it is two words that have a different meaning when used together than when used separately. For example, the words international and adoption have their own meaning as individual words, but when combined mean an adoption where the adopter and adoptee live in two separate countries.