Need to Back-up prior to updating WP 3.5.1

Hello, I’m a new user of WP trying to update my the version I’m using, but I’m stuck on the preliminary back-up that is necessary to safeguard against data loss. I installed the
WP-DBManager but the process is puzzling me.
and got the following warning:

Your backup folder MIGHT be visible to the public
To correct this issue, move the .htaccess file from wp-content/plugins/wp-dbmanager to D:/Hosting/8617562/html/RabbiBeliakBlog/wp-content/backup-db

The warning makes no sense to me since I don’t understand the backend of WordPress yet. I am not a code/web design person but I’m pretty good navigating software. Is there an easy step by step how-to you can send me for what I need to do next. And, if there is anything I need to be aware of regarding the subsequent update I will do, please let me know that as well.

Thanks for your time.