I have been unable to find any documentation on record level security. I know that it somehow involves calculations but if anyone can provide some simple examples I would appreciate it.

SecurityLevel = 1 and gUserID <> "admin"

The above is a simple boolean equation to establish the security. Assuming that the SecurityLevel field is set to 1 (i.e. the record is secured), and the gUserID is "admin" the equation will evaluate to 1, thus allowing access.

In the case of record level security any equation that evaluates to 1, or Yes or True will cause the record to be secured, and thus unavailable.

Since the value of the equation can either be 1 or 0, any given record will either be available or not.

To figure this out for yourself, simply write down the criteria that would secure a particular record, and also write down the criteria that would make records accessible. You then just need to translate that into a boolean expression.