Having a clearly defined research question BEFORE you jump into research will save you time, effort and aggravation. If you try to research a subject area like second language acquisition, you might find yourself flooded with information, and the sheer task of identifying the best and most valuable resources will be staggering. A clearly defined research question, e.g., "Does the age of an internationally adopted child make a significant difference in the child's development of oral and written language skills?" will help focus your research task and save you time and effort.
With a question in mind, you can do some preliminary searching in the Libraries' catalog or a periodical database just to get some idea of the literature that will be available for your research. This first rough search can give you some ideas for modifying your search, if necessary. For example, a quick search in Academic Search Complete a general periodicals database, using "second language acquisition," yields over 4000 search results.
A search utilizing terms from your question such as "age," "international adoption" and "language skills" retrieves four articles. However, one article includes a bibliography of 59 citations and another lists nine articles in which the original article retrieved by your search was cited. Two of these articles were published in 2009. A search set of less than 100 citations that deal more directly with what you are interested in researching is certainly more manageable than a search set of over 2000 citations.
So, a little planning time before saves a lot of research time afterwards.
It might seem funny to think about search strategy before you even begin to search a database. However, thinking about key words that define your question, synonyms, and ways of combining these keywords beforehand will help you modify your search results on the fly, depending on what you are retrieving.
Consider search words and phrases and combinations you might use to search for information on your topic. Most databases allow keyword searching, which basically allows you to enter any word(s) or phrase(s) or combinations thereof for very broad search results. Databases also allow searching by controlled vocabulary such as subject headings or descriptors. The most widely used subject headings are the Library of Congress Subject Headings (LCSH); we have the most recent set of LCSH in the Young Ready Reference Collection (LC 26.7 :). A subject database might have its own thesaurus. If a database you are searching offers a thesaurus or subject heading list, consider consulting it for language to make your search targeted and precise. Often a thesaurus offers suggestions for broader, narrower and related terms that can be used to modify your search, if needed.
Check out Database Searching for tips to help you do the most efficient and effective searching whether you are searching Google or any of the UK subscription databases.