Each event within the heptathlon are generally the same as for the individual events themselves.
A few exceptions do exist: Most notably, runners are allowed two false starts instead of one, while competitors receive only three attempts in throwing and jumping events. Competitors cannot pass on any event. Failing to attempt any single event results in disqualification.
Points are awarded to each athlete according to her time or distance, not her placement in the field, according to pre-set formulas. Those formulas have been revised frequently over the years, making head-to-head comparisons of many heptathlon performances difficult.
If there is a tie in points after seven events, the victory goes to the competitor who out-scored her rival in more events. If that tiebreaker results in a draw (3-3 with one tie, for example), the victory goes to the heptathlete who scored the most points in any single event.
If this has whet your appetite and you are good at maths then this document from the IAAF may interest you.