You can search across multiple databases by using Library Articles Search. This allows you to search across thousands of publishers and millions of documents. As part of your search, you can limit your results to articles from scholarly journals, from newspapers, or to articles that are available fulltext.
Things to remember:
Library Articles Search is a very good way to start researching a particular topic.
Library Articles Search is great for multi-disciplinary and inter-disciplinary research.
Library Articles Search does not replace subject specific databases for specialized searching, so don't forget about the Avery Index, JSTOR, ScienceDirect, or any of those other standards you've become accustomed to using.
Library Articles Search is not a book catalog (though it does contain ebooks); if you want print and ebooks, search in the Library Catalog.