Well ladies and gentlemen, Minecraft 1.8.1: The Adventure Update is here and with that there's a new version of ModLoader available. So if you've been having trouble installing mods after updating to Minecraft 1.8.1 - now you know.
For those of you who are still in the dark about ModLoader - it's a piece of software required for nearly all of the Minecraft mods available.
Download & Installation Instructions
1. Download ModLoader for Minecraft 1.8
2. Press start.
3. Press run.
4. Type %appdata% into the space provided.
5. Open .minecraft
6. Then bins.
7. Then open minecraft.jar by using winrar or 7zip.
8. Drag the contents of Modloader into the minecraft.jar that is opened by winrar.
Download it here