Why would you want to use ModLoader when we have native mod support?
Create a folder called mods in your root directory and a subfolder named modname. (Replaced by your mod's name of course)
Create an iwd file and put all the contents of your mod in there. (The root of the iwd should be the root of your mod folder.
When in the main menu, pop the console and type fs_game mods/modname;vid_restart
Create a game, be the host and your mod is loaded.