Hi there and welcome.
I don't know about a dummies guide but check out the iPad User Guide in iBooks, just make sure that you get the correct one for your version of iOS, they are both free so not a major problem if you get the wrong one.
There is lots of good advice and info on here plus plenty of members all too willing to help with any problems.
Remember, search is your friend. If you can't find the answer you need and you post a question then give as much info as you can to help members help you i.e. iPad 1 or 2, iOS version and name of app if the problem is with a specific app........and please don't forget to read the rules
http://www.ipadforums.net/forum-rules-help-info/2119-forum-rules-everybody-please-read.html
These are the hacking section rules for all you jail breakers (and would be jail breakers)
http://www.ipadforums.net/ipad-hacking/2892-hacking-section-rules-please-read.html
We also have an app for this forum. The link to download the app is:
Discussion Forum for iPad Users for iPhone, iPod touch, and iPad on the iTunes App Store
You can download the manual for your iPad here
http://support.apple.com/manuals/ and in iBooks search for "iPad user guide for" and you will find free comprehensive manuals for both iOS 4 and 5.
If you have other Apple products or are interested in other Apple kit then why not join our sister forum too at
http://www.appleforums.net/
Finally, if you still haven't had enough, how about a video explaining about our other forums (note:you may want to play this at half speed but hey, why shouldn't Phil be excited about our forums!)
The Archangel