Jessica,
I like www.morningstar.com as a basic data source on ETFs. They have a standard presentation that makes it easy to compare funds and their information is timely. There are some limitations to the data so you should always go to the ETF sponsor site to get the latest fund data if you have any doubt.
For analysis, comments, and views I suggest a visit to www.indexuniverse.com where you will find contributors like Rick Ferri ,who will teach you all the basics for ETF investing, and Craig Israelson, an academic who does interesting research. It's a very good site with a broad reach of content from simple to quite sophisticated.
Scott