Connecting to external monitor
I think the answer to your queation is "You don't. Apple does it for you".
I just tried out my VGA adaptor to connect my iPad to my big screen TV and was less than impressed. It would be nice if Apple would give details up front about what a device will & won't do.
This is what I found out:
After hooking up the iPad to my Sony TV, turning on the iPad & selecting the appropriate input, my TV said it had no signal.
I selected "Videos" on my iPad. Selected a movie I had purchased from iTunes. Got message on iPad that selected monitor was not authorized to play copyrighted material. Huh? Guess I'll have to look for a work-around to play MY movie on MY iPad via MY TV. Apparently only an Apple TV is acceptable.
Selected "Videos"' then "Podcasts". When I selected a (previously downloaded) video podcast, it DID appear on my TV, but the quality wasn't very good on my big screen HDTV.
Next, I tried YouTube. On the iPad I navigated to the video I wanted to watch. Nothing appeared on the TV until I selected a specific video. Then the iPad screen went blank and the video appeared on my TV. (The quality, streamed through 3G, was atrocious).
I then went to my Photos. I was unable to view any of my photos UNLESS I played them as a slideshow. I selected an "event" with 10 photos & selected "slideshow". This time I saw my photos appear on both my iPad AND my TV. Since slideshow parameters are set in the overall "Settings" site, there are no controls present when the slide show is actually playing. I found I could stop / freeze the show on a particular photo with a tap to the iPad screen, but couldn't easily restart the show, nor could I zoom in on photos being shown on the TV screen.
It would seem Apple has put strict limits on both WHAT media can be viewed on an external monitor and HOW it can be viewed. I was hoping for much more versatility than what I've experienced today. I'd really like to be able to play all my movies and any TV shows I've purchased on my big screen TV. I'd also like to look at individual photos - zoom in on parts of them - and step through a slideshow at my own pace, pausing and restarting at will.
So that's it for my "first-look" ... Not real happy with what I've got so far. I'd be very interested to hear what others have found.