Any USB or PS/2 keyboard will work very well with your Dell computer.
Any USB printer will be easy to install and use on your Dell computer.
No, just about any keyboard will work with a Mac.
Yes. As long as it runs through a USB or Bluetooth connection it should work fine.
Yes, an iPod touch will work on a Dell computer as long as it has iTunes loaded onto it.
They aren't the best computer to go for, but they work okay (they're not made very well)
Some of them do if they are in a store that is strictly computer like Dell. If they work in a mass merchant such as Best Buy, they are on hourly rates.
The dell Optiplex is great,for this kind of work
no
Any antec tower that is ATX size will fit your components.
A keyboard is a peripheral device as it is connected to the computer system. It is used for type work up to the computer.
Yes
Picasa and IPhoto are two different programs. Picasa will work on a Dell, but many Mac users have problems with it. IPhoto will work on a Mac, but many Dell users can't use it.