If you're like me and you use numbers to try and back up your arguments, you'll probably run into the issue of not being able to find the numbers you're looking for from time to time. Here's my current list of hockey resources, which I'll put up soon on the right side.
Behind the Net is probably the best website for hockey-related numbers out there. It lists lots of per-sixty-minutes rate statistics like plus minus and goals, as well as breakdowns of 4-on-5, 5-on-5, and 5-on-4. It also has Corsi and GVT and Zonestarts, among other numbers. The author, Gabriel Desjardins, also runs the Behind the Net blog. And if you simply can't find the information you're looking for, you can send him a nice email asking for some information and he can probably pull it up for you.
Olivier Bouchard runs his own blog, and actually records the Canadiens' scoring chances, among other things. His work is in French though, so chances are you'll need to keep Google Translate handy.
Tyler Dellow on his blog does some interesting statistical analysis of various trends and players.
Brodeur is a Fraud has some nice insights into goaltending.
Vic Ferrari started the site Time on Ice, which can give you shift information about specific games. He also has a blog. Maybe most importantly, though, he has player scripts that can let you find information like Fenwick and Corsi and do WOWY (with you without you) analysis. He explains how to use the scripts in part one and part two.
The Copper and Blue is an Edmonton Oilers blog that occasionally runs analysis in the grander scheme of things. Even if their analysis in Edmonton-centric, they have a plethora of ideas one can always apply to a different team.
Tom Awad (the creator of GVT, goals versus threshold) and others write at Puck Prospectus, which has all sorts of analysis and innovative player rankings.
James Mirtle occasionally does similar work for the Globe and Mail. In the same vein, bloggers on sites like Japers' Rink, Pensburgh, and other sites will also venture in new realms.
If you want to find how often a forward played with another forward, or a defenseman with another defenseman, Dobber Hockey is the place for you.
If you want to find how many players did something with certain parameters, or just what a certain player did in a given year, look at Hockey Reference. Or maybe Hockey Analytics.
Capgeek has all your unofficial salary cap information.
And don't forget the NHL.com has lots of different statistics in their online stats engine, including home/road, by manpower, and by-period splits, in addition to the general goals-assists-points-PIMs.
I know that I've missed some. If you know of another helpful site, please add it in the comments.