I use iPads, but most of the useful apps are available on Android too:
Dropbox for sharing files
PlainText for taking notes, with auto syncing to your dropbox folder
GoodReader for viewing files and annotating PDFs (great for running records). Syncs with Dropbox.
All of our teachers have them. We have grade level shared Dropbox folders for sharing running records (annotated in GoodReader), mentor text ideas, trip forms, etc. PlainText is great for note taking since all notes are autosaved to Dropbox, which can then be shared....
There are a bunch of other apps I use, but not sure if they are Android based too (like the McGraw Hill Everday Math apps, SoundNote, Notability, etc).
We have a site built around our staff iPad initiative (ps10ipads.wikispaces.com). There is an "Apps" page that might be useful to you. Again, we're iPads but a lot of app developers are supporting both platforms.
Check out this page...
I'm in college and i actually have used Dropbox before and its a great tool and its easy to use.
Christopher is right. Many of the apps that teachers use on the iPad are available as android apps. Some specialized apps are not yet available for android tablets.
You should also remember to use the Flash enabled sites on the web using the browser in android. For example, one of the greatest apps for young kids on the iPad (SuperWhy from PBSkids) is available at no cost using the flash enabled version of the pbskids site. Another amazing site is related to the awesome iPad app called The Elements. Best of all it costs nothing.
My 2 cents
So much to consider. What is the main objective? eTextbooks? eBooks? Files for class? Some browsing? eReaders will do this in color for $100 - $250
Need More? Apps for review? Better browsing? Some content creation? Then a tablet is a step up.
Tablets -> 3 major players Apple - Android - Blackberry All with unique benifits. Need Flash player? Then forget iPads.
Screen sizes vary from 7" to 10". Resistive touch? Capacitive touch? Prices range from $100 to over $800
Need to do "real work"? Create content? Editing? Netbooks (10" screen) can be had for as little as $250 with quality battery life and offer more flexibility. They also make nice eReaders and content carriers.
The secret to success here is to identify the true need and purpose of the device. Tablets/eReaders are cool and fun. They are great for playing games, have a variety of educational apps, listening to music/podcasts and watching video. Netbooks/Laptops can be easier for an IT dept. to manage and are a better choice for content creation...in my humble opinion.
Our CTO was just at Google IO last week where Google made some important announcements about Chromebooks and education. His blog post talks about the strengths of Chromebooks vs. tablets in a school setting and whether it is time for schools to go all-in on the web. http://bit.ly/l72a9h