I use WordPress for my Blog if there is a update notification plugin and theme. I always click update. I do not know if it's right or wrong. Please advice. Thanks
As long as you have the site and your database backed up to your own computer, you should update whenever an update comes out. I wouldn't do it without a backup, though - if someone screws up and you have no backup, you have no site. (You should have your database backed up and emailed to you every day - there are plugins for that - and you should always have a complete file/directory backup whenever you make any changes.)