Hi,
From query analyser you can do this:
execute sp_msforeachtable 'dbcc dbreindex( [?] )'
You can schedule this as a job by entering this as the query in the job-step.
Or you can achive the same result by creating a maintenance plan(Management | Maintenance Plans) that does Reorganise data and index pages.
On completing the maintenance plan wizard, jobs which schedule this are created.
HTH
Regards
David