I agree with Leo, the sysjobs and sysjobhistory tables can be quite useful. Here's a query I wrote which will return the average, max, min, range and standard deviation of step runs in milliseconds over the course of given date range for a given job. Very useful when determining which parts of a job are taking a long time.

SELECTAVG(sjh.run_duration) AS avg_run_duration_ms,

MAX(sjh.run_duration) AS max_run_duration_ms,

MIN(sjh.run_duration) AS min_run_duration_ms,

MAX(sjh.run_duration) - MIN(run_duration) AS range_run_duration_ms,

ROUND(STDEV(sjh.run_duration),2) AS stdev_run_duration_ms,

sjh.step_id, sjh.step_name

FROMsysjobhistory sjh

INNER JOIN sysjobs sj ON sjh.job_id = sj.job_id

INNER JOIN SANDBOX.dbo.Numbers n ON sjh.step_id = n.Number

WHERE sj.name = 'xxx' -- put job name here

AND sjh.run_date BETWEEN 20120616 AND 20120716 -- put date range here

AND step_id <> 0

GROUP BY sjh.step_id, sjh.step_name

ORDER BY step_id