SharePoint 2010 Capacity Planning - SharePoint Joel's

http://www.microsoft.com/downloads/details.aspx?FamilyID=990041E5-0A73-4D2F-895D-2232D1A229F5&displayLang=en

http://www.microsoft.com/downloads/details.aspx?FamilyID=FD686CBB-8401-4F25-B65E-3CE7AA7DBEAB&displayLang=en

http://www.microsoft.com/downloads/details.aspx?FamilyID=FD1EAC86-AD47-4865-9378-80040D08AC55&displayLang=en

Don’t forget the tool of HP and all this articles

SharePoint 2010 Capacity Planning - SharePoint Joel's SharePoint Land

http://www.sharepointjoel.com/Lists/Posts/Post.aspx?ID=332