There are over 70,000 entries in this index, and they're available through a keyword search. The keyword search also a couple other search options, including date range and topic inclusion.

I did a general keyword search for "Roosevelt" and got over 2800 results. The first 250 results are listed on the results page. Results include relevance score, hyperlinked reference number, record description (some of these can be quite extensive) and date. Click on the reference number to get more detailed descriptions, keywords related to the item, and the access status of the item (open or not.)

In addition to the keyword search of the papers, this site also contains a lively biography of Churchill (did you know his wife once threw a dish of spinach at him?) and an overview of the papers.