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
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/
Regarding USB port, I, too thought that I would need a USB port with my initial taking on tablets. Prior to getting the ipad, I purchased a droid tablet that had all of that. Since than, I changed over due to personal preference and use. There are many work around tasks that you can do not having a USB port. What exactly are you looking to use it for. If you would like to transfer docs/photos easily from your ipad to PC- you should check out the DropBox App, one of several apps that can help you. It easily syncs all your devices that has this app and can easily pull up pics etc.