1) I have not heard of any good camera options for the iPad 1. Though there was a Camera A and Camera B app early on that would work so that the iPad could use an iPhone camera. Don't know if it is still around.
2) Only HP's AirPrint printers are directly compatible with the iPad.
iOS: AirPrint 101
There are a couple ways around this. One is to use an printing app on the iPad. The current favorite is Print and Share. It will work with most wi-fi printers, and those that it won't work with can be made to work with an additional program on the computer.
The second method is to load a program on the computer that will emulate an AirPrint compatible printer. Your computer must be on and have the printer available to it. The cheapest (free) is Airprint Activator. More features can be had with FingerPrint (mac and windows) and Printopia (mac only).
I use Printopia, and love it. Tim likes Fingerprint, but he has Windows, and doesn't know what he is missing.
There is a third way. A few printers (mostly HP's again) can be set up with their own email address. PDF attachments can be sent via this address to be printed. The last review I saw said it could be quite slow (big files not recommended), and sometimes the emails got lost and never printed. The advantage was that you could literally send/print from anywhere you have an internet connection.
