A few resources:

Mass Deployment of the Microsoft Dynamics AX Client: https://mbs.microsoft.com/customersource/documentation/whitepapers/daxwp_massdeploymentoftheaxclient.htm

*Note this is for general review of mass deployments and is not specific to AX 2009
Silent installation - http://msdn.microsoft.com/en-us/library/aa496627.aspx

One important note regarding syntax

For upgrading existing clients:

...\Setup.exe LogDir=C:\log HideUI=1 AcceptLicenseTerms=1 LicenseTermsVersion=en-us UpgradeClientUI=

For Installing new clients:

...\Setup.exe LogDir=C:\log HideUI=1 AcceptLicenseTerms=1 LicenseTermsVersion=en-us InstallClientUI=