HELP! before i buy

Before I buy a WD my world book 1 TB HDD I have a few questions, I am new too the whole external hard drive thing and im not very computer savvy, any help would be appreciated thanks in advance.
#1 is the my world book HDD compatible with the WDTV LIVE
#2 is there any way too disable the whole back up all my computers on my
Net work thing, I just wont too drag and drop files too it and I have no need
Too back up anything

#1 - Yes, it is compatible

#2 - Yes, you can opt not to use as a backup and just as extra storage.