How Often Should I Resubmit My Optimized Site?, Submission Frequency

[Hurri]

Hello there! I am a web developer and recently my boss asked me the following:

Since we submit an optimized site what is going on with spiders, and that is how often do they spiders pass from my site, do we have to resubmit the site to engines and directories, will the spiders pass forever and if that happens should i refresh the site's content?

Could anyone help me?

[megri]

Try to use free submission services (http://www.seowebdirectory.com/SEO_Tools/URL_Submitter/index.html)