You first need one or more apps on the iPad that supports the type of file that you want to add to it - it doesn't have a 'file system' like a 'normal' computer, everything has to be stored in an app.
To sync photos to the iPad's Photos apps, then if you are on iTunes 11 on your computer then you may want to re-enable the left-hand sidebar via View > Show Sidebar (option-command-S on a Mac, control-S on a PC), which might make it easier to navigate and my instructions may make more sense.
Connect and select your iPad on the left-hand side of your computer's iTunes (if you've enabled the sidebar), and on the right-hand side there should be a series of tabs, one of which should be Photos - if you select that tab you can then select which photo folders to sync to the iPad. There is a bit more info on this page. You will need to sync all the photos that you want on the iPad together in one go as only the most recent photo sync remains on the iPad - synced photos can't be deleted directly on the iPad, instead they are deleted by not including them in the next photo sync.
To get documents on the iPad, then how you do so will depend upon what the app supports e.g. transfer via the file sharing section at the bottom of the device's apps tab when connected to iTunes, via your wifi network, email, dropbox etc. For PDFs you can use the free iBooks app and sync via iTunes - you can add PDFs to the Books part of your computer's iTunes library via File > Add To Library, and then with the iPad selected on the left-hand sidebar use the Books tab to select and sync them to the iBooks app
sorry guys I'm new to the Apple world and haven't managed to transfer a large volume of files (pdfs, images, etc) from a PC (Windows Vista) to my new ipad.
Any help is well appreciated.
I've found that the best way to move documents and photos from the iPad to my iMac is to get a Dropbox account. It's free and gives you 2 GB of storage to start. It's easy to use, just move a file into the Dropbox folder in your finder window, and in about 5 seconds, that document will be in the Dropbox App on your iPad. For me, it's an essential app.
Have you actually tried using iTunes?
For each file type find an app that deals with them e.g. goodreader for PDF, then connect your device to your PC and open iTunes, select the device under the device menu on the left hand side of iTunes and then select the apps tab on the right hand side near the top. Scroll down to file sharing and there should be a list of apps. Select the app for the file type and use the add function to add your files.
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