When you run the products and technologies wizard on the new WFE and join it to the farm, all IIS sites will automatically be provisioned on the server, and all features deployed through SharePoint will be deployed on the new WFE. That server will match any existing server in the farm from a base configuration standpoint, excluding anything you've done manually on each of the other servers (but you shouldn't be manually deploying things anyway).
The base services will be started, and if you want any additional services to run you will need to go into "Manage Services on Server" and start them.
It should go without saying, but I will say it. Make sure you're running the products and technologies app as the installation account, and that account is a local admin; otherwise things will likely not provision correctly.
If you've got web applications provisioned as HTTPS, you'll need to take the appropriate measures to get the SSL cert configured on the servers; that is something SharePoint won't do for you.
Once you've done this, simply add that server into your load balancing array and you're good to go.