We own several grammar textbooks and workbooks in Maruzen eBook Library. First click this link and log in with your PennKey, then select アルク as the publisher on the left-hand side of the page. You will be able to view books such as the どんな時どう使う日本語 series.
Light novels and other fiction can be read online for free on these sites. Note that these works are self-published online.
NOTE: PLEASE "LOG OUT" of the book viewer when you're done! Otherwise no one else can view the book even if you close the window. You can do that by clicking the SMALL YELLOW 閲覧終了 button at the top right of the page! Click "OK" on the pop-up message, then close the window after the book disappears from the viewer.
The Maruzen eBook Library interface is only available in Japanese. Below are some helpful database terms and their English translations.
Marzuen's eBook Library offers several series of JLPT preparation books. You need to click this link and sign in with your PennKey to view our ebooks. You can click on the left side of the page to narrow down by publisher: select ユーキャン for the U-CAN general JLPT prep series, or 三修社 for the Kanji master (漢字マスター) textbook series.