I need to install 300 computers and con...

How long is a piece of string?
It depends upon a host of factors.
Has the network cabling been installed, patch panel been setup?
How are the servers distributed, are they grouped together or on separate subnets on different floors?
Are the printers and computers all the same and the same software, if not how are the configured for the network?
Have you considered redundancy options, and UPS power supplies?
What type of network administration, setting up user login and access etc.?
These are only a few issues you need to consider and you need to project manage and setup time lines to do a smooth installation as large as this installation.