What is the best external easier said than done drive for mirroring folders?

My mom have had troubles next to her hard drive failing. I'd approaching to get her an external easier said than done drive to backup her data. What I'd really close to, however, is for that drive to just mirror a couple of folders (say her My Documents) so that anytime a folder is added or udpated, it automatically goes to the external drive as powerfully. I don't think she wants super-powered RAID drives aimed at a corporate market. I basically want something simple that I can walk her through the set-up once and own it just work for her.



Any recommendation?

What is the best external easier said than done drive for mirroring folders?

Many of the articles and review in the Storage division of ExtremeTech are about external hard-drives:



http://www.extremetech.com/category2/0,1...



ConsumerSearch have an External Hard Drives section:



http://www.consumersearch.com/www/comput...
Most of the main label tricky drive manufacturers produce lawfully high feature external drives, however my favorite one for ease of use and reliability is the tentative Western Digital's MyBook series hard drives. They come near backup software and it can be automated, so the user has to do zilch and the software will backup the valuable notes on the computer.