1. Click Research, and select LOC to go the Library of Congress Online Catalog.
2. Click on the type of search you want (either Guided or Basic), enter a search term, and click OK. (You will want to note that you can search for an ISBN number, to locate the record for a book you are using as a source.)
3. In the Search Results listing, click on the work you want to include in your Citation database.
4. Set the option to display the Full Record, and then highlight and copy the record.
5. In Citation, click Research, Import Record in Citation.
6. Review the record to make certain the information is correct.

For example:

We went to the Library of Congress Online Catalog, and ran an author search for Diamond, Jared M.:
This search returned a number of books by Jared Diamond:
We then clicked on the listing for the book Collapse:
We copied this record, and imported it into Citation:
We also could have checked the records we were interested in, and then clicked on the option (at the bottom of the screen) to Print or Save Search Results: :
This option will display all the records (or all the records you've selected). You can then copy these records and import them into Citation.