The 33 1/3 book series is one of the best sources for album reviews. You can search the full list of titles here.
Selected books in the series:
You can search CDs and vinyl records on the Music Library homepage. Click the "recordings only" button to limit search to CDs and records.
Many CDs have liner notes with information and musical analysis.
You can search album reviews on these websites:
Dissertations can be surprisingly good sources for your research, since they are scholarly, can be very focused on particular bands/artists, and often shed new light on a topic.
For very recent bands/artists, current newspapers and magazines are likely to be the best sources for information. Some newspaper databases focus only on current content, and others include older issues; coverage is indicated below.