First, you will need SteamCMD. It can be downloaded from the official Steam website:
http://media.steampowered.com/installer/steamcmd.zip

Extract the ZIP, and put steamcmd.exe on your desktop for now.

Now, you're going to need to create a folder for your server to be held in. It should be empty. The rest of the guide will assume you are using "C:\steamcmd" as your folder. Now take steamcmd.exe from your desktop, or wherever you put it, and place it in the steamcmd folder.

This is the longest part of the guide, and it heavily depends on your internet speed. Open up cmd (Command Prompt) as administrator, then type the following commands:

• cd C:\steamcmd
  
• steamcmd

Now the window will change into a little thing saying steamcmd. Now use these commands:

• login anonymous
  
• force_install_dir ./TF2/
  
• app_update 440
  
• quit

Congratulations! You now own a TF2 server. Simply open up C:\steamcmd\TF2\srcds.exe to start your server. Now you can install sourcemod, and follow TF2 server setup guides.

Note: if you are behind a firewall/NAT you will need to forward ports. Hamachi is a way around this, but anybody connecting will need Hamachi.

I figured out how to set up servers by reading this article[rnediafire.com]. I do not take any credit for this information, and I just wanted to help others learn how to make a TF2 server.

A server just isn't good enough for public use unless you have sourcemod installed. To install sourcemod, you need to get the following:

http://www.sourcemod.net/downloads.php
http://metamod.org/

Simply put the metamod and sourcemod files into your server's directory. You now have sourcemod installed. If you want to setup sourcemod, please refer to this server forum:
https://forums.alliedmods.net/