JSTOR (short for Journal Storage) is a great resource for full-text journal articles in humanities and social sciences.
In addition to full-text of almost 2,000 academic journals, JSTOR encompasses books and other primary sources.
Keep in mind, for most titles JSTOR does NOT include full text of the most recent 3 to 5 years.
Add snippets of the articles in your search results to your results page! If you want a glimpse into an article in your results list without taking the time to click into it, checking the "Add Snippets" box at the top of the results will give you that glimpse.
Quick options appear to the right of each item in the results list (just like it appears here). These options include downloading the PDF of the article, if you want to get it now and look it over later, adding the item to "My Lists" (you will need to make a free JSTOR account for that), and citing the item in several different styles.
If you need historical documents for your project, you can limit your search results by publication date. This option appears on the left-hand side of the screen. Just enter the date range (in years) that you are looking for, and voila! Historical documents appear.
JSTOR Advanced Search has a look and feel that is similar to EBSCOhost databases such as Academic Search Elite: individual search boxes connected with the Boolean operator AND. You can add fields with the blue button below the bottom search field, as well as change the Boolean operator that connects each field. AND will probably be the most useful, however. You can use OR and NOT within the individual search fields.
Note that the "Full Text" next to the search boxes does not mean that your search results will pull up only full-text articles. This "Full Text" means that JSTOR will search the entire text of an article for the search terms you use. If you want ONLY full-text articles in your results, use the "Select an access type" drop-down menu. "Read and download" is the default, and this is where you want to leave it if you want to be able to access PDFs of articles. However, UI Libraries may have access to some of the non-full-text content through other databases using UI Link, so select "All content" from this menu if you don't want your results to be limited by full-text only.