Starting with the basics:

Ask your TF2 server provider if your server is Windows or Linux based. If you're more tech savvy than most you can figure this out on your own by going to the root of your TF2 server via FTP. Look for an ".exe" file. If you have an .exe file then your TF2 server is Windows based. If not, then it is most likely Linux.

Based on that information you are ready to start downloading the competitive TF2 things below.

[b]Unofficial ESEA Season 13 Whitelist (updated November 6, 2012)[/b]
https://dl.dropbox.com/u/1982709/item_whitelist.txt

[b]SourceMod[/b]
[i]Make sure you choose the correct OS version for your server[/i]
http://www.sourcemod.net/downloads.php

[b]Metamod[/b]
[i]Make sure you choose the correct OS version for your server[/i]
http://www.sourcemm.net/

[b]SDK Hooks[/b]
http://forums.alliedmods.net/showthread.php?t=106748

[b]TF2 Match recorder[/b]
[i]Records STV when in tournament mode[/i]
http://forums.alliedmods.net/showthread.php?t=92716

[b]Supplemental Stats[/b]
[i]Records extra stats in log files like damage output and heals[/i]
http://tf2logs.com/track?url=/files/supstats.smx

[b]SoapDM Mod[/b]
https://github.com/Langeh/SOAP-TF2DM/downloads

[b]MGE Mod[/b]
https://forums.alliedmods.net/showthread.php?t=154755

[b]Mid-Fight Trainer[/b]
[i]Versatile Sourcemod plugin for practicing midfights[/i]
http://teamfortress.tv/forum/thread/974-mid-fight-trainer-practice-your-mid-fights