Appadvice.com is an EXCELLENT resource for iPhone/iPad apps.
You can search for apps in a few different ways: app reviews, app lists, app guides, and an app base.
App reviews: Read their reviews of newly-released apps.
App charts: Search through the App Store charts by category just like you would within the App Store itself.
App lists: One of the coolest features of this site...they handpick apps to fit your lifestyle. Find "apps to help you be green", "apps for car drivers", "apps to plan events", and so much more!
App guides: These guides are all "best of" apps for various topics. For each one, they break down the apps by rating: essential apps (the top 2-3), notable apps, decent apps, and other apps. Check out their appguide for best handwriting apps on the iPad.
App base: Browse new apps (free or paid) by category.
Apps Gone Free
Appadvice has also released a free iPad app called Apps Gone Free. Ann Gustafson brought this great little app to my attention! Each day, when you open the app, it lists about ten paid apps that are free for that one day only. Some usually cost 99 cents, but there have been some that usually cost around $5. Many of them are silly games, but once in a while you find a really interesting app that's worth checking out.
Edtechteacher: The iPad as...
Edtechteacher.org offers a lot of teacher professional development related to technology and the use of iPads in the classroom. They helped to coordinate the Shrewsbury Summer Institute and are currently offering the T21 program at Oak.
They are also hosting the iPad Summit 2012 on November 7-8.
The Edtechteacher website has a lot to offer for teachers. One of their best resources though is their "The iPad as..." page. They categorize iPad apps by learning objectives, as seen in the screen shot below.
For each iPad learning objective, they list recommended apps, give a brief description, and rate its usefulness and ease of use. A site like this can be really handy because apps are always improving. Just when you thought you found the perfect app, another one comes along that's even better. We don't have time to keep track of all of these apps, and we don't have to. Edtechteacher will update these apps as newer, better ones come along. Below is an example of some apps they recommend for recording and editing video on the iPad.