Jethro Carr offers a useful guide to personal computer vulnerabilities in Attack vectors for personal computers.
For non-technical readers it’s a good primer, for more technical people it’s a nice reminder of the things you should guard against.
Carr points out these threats are insignificant compared with the computer owner’s behaviour. And as he says:
never forget the biggest weakness – beating a user with a wrench until they give up their password is a lot cheaper than developing a sophisticated exploit if someone just wants access to some existing data.