Apple, Inc. has posted the iPad2 User Guide for iOS 4.3 software. This 198 Page guide is a 16MB download. Everything from an overview of the iPad2 to a review of the included applications is covered. There are even some tips on troubleshooting.
If you want to read and use the PDF guide on your iPad, open this post in the safari browser on your iPad and click on this link. After the PDF loads, at the top right of your browser, you will have an option to open your PDF in a different app. Tap on “Open in…” Choose the app you want to use to open the PDF. If you do not have any paid apps like GoodReader or ReadleDocs, you can open it in iBooks. Then, you can have the manual available on your iPad whenever you want.