Where does one begin to look for WordPress plugins that do all the cool stuff seen on other blogs and get the full functionality envisaged when first planning your blog?
If you know what you are looking for the WordPress Plugin Directory is your primary source of plugins.
At the time of writing this post there were 13, 817 plugins listed in the directory, so searching through all these can be a little daunting to say the least, let alone trying all the different plugins related to your search to find the one that works and best suites your needs can be very much trial and error.
Another suggestion I have is to go find and follow other blogs/websites that focus on WordPress and often write articles highlighting the most popular or latest plugins on the market.
One example of a resource I have recently found is Site Sketch 101. The article that led me to this website was entitled The 15 Best WordPress Plugins To Use In 2011 by Nicholas Cardot. It is a great example of one way to find the latest and greatest plugins, that have already been tried and tested by someone else!
Another great resource that I have used for many years now is Smashing Magazine.
If you have any other great resources for finding WordPress plugins, I would love to hear about them :)