Customers always ask how many servers do I require for my SharePoint setup? Also other questions that come up are about CPU, Memory and Disk capacity.

Microsoft has 2 documents which help you lead in deploying the right size solution for your business.

The documents contain worksheets to help you ask the right questions about the SharePoint implementation and the key factors that make up the infrastructure.

You can download the two documents from : http://technet2.microsoft.com/Office/en-us/library/a76963dc-1cd0-4aff-ae9c-3736d89c42441033.mspx?mfr=true