There's a lot of exchange traded fund (ETF) information out on the web. A lot of it is not worth reading and a lot of the good stuff is buried so that you have to dig deep to find it. Here's a list of great resources for the aspiring ETF investor.

iShares
Barclay's Global Investors provides an extensive collection of Exchange Traded Funds (ETFs). Consider buying these over other ETFs because of their popularity and institutional support.

iUnits
The Canadian versions of Barclay's Global Investors iShares.

MartketWatch.com
The ETF and mutual fund subset of investing news from MarketWatch. A good place to get acquainted with ETFs and to read the perspectives of writers with different biases.

BigCharts.com
I don't do much in the way of technical analysis, but I still get a kick out of looking at charts. It's also handy to compare the performance of similar ETFs. BigCharts is my favorite charting site.