indeed rule 1 never use the same password on any other board (i used to root a few people a few years ago because they was dumb to use it on every site, satanwarez owner did and this got me his root on his server, email and credit card details).

also ip and password protect any of your admin panels, stay up to date with your forum software.

and there is many ways to secure your server, if you need help let me no.