More about SharePoint Workflows & Scheduling

http://office.microsoft.com/en-us/sharepointdesigner/HA101005871033.aspx

http://parkesy.wordpress.com/2008/07/18/sharepoint-incoming-emails-automatic-workflows-sorted-3/

http://blogs.interknowlogy.com/rodneyguzman/archive/2007/03/20/12405.aspx

http://www.articlealley.com/article_661904_10.html

http://stackoverflow.com/questions/349387/workflow-auto-cleanup-timer-job-does-not-run

https://www.surfgroepen.nl/_layouts/help.aspx?lcid=1033&cid0=MS.OSS.manifest&tid=MS.OSS.HA10154424

http://www.finalcandidate.com/en/tandp/Pages/SharePointWorkflow.aspx

http://groups.google.com/group/microsoft.public.sharepoint.portalserver.development/browse_thread/thread/73e1802ac9b4ae18

http://www.devx.com/webdev/Article/34032/1954