I need extra space for my Family Tree Maker software. Am considering adding an external drive to handle all of my pictures and data. Has anyone done this and is it possible.

Yes, it's very possible and extremely straight forward.

I agree. Very simple. I have two external USB harddrives myself. One primarily for photography, and another for miscellanea related to musical composition. Works out very good.

In addition : you can get another hard driver and one external enclosure and can get a high space area :)

I also have an external USB drive. Very easy to install and use. One alternative, if you have a home network, is to use network attached storage (NAS). This is a hard drive with a CPU connected to it that can be attached directly to your router. In this way, the drives can be shared by all the PCs on your LAN.

Hmmm great :) very helpful

One other nice thing with a second hard drive is you can do a image of your operating system and the programs you have installed as a back-up in case c-drive goes up.
The only question I have is do you already have a 2nd hard drive in the PC?
A 2nd internal would cost less and is not that hard to install