Here's what I did.
1. Download Minecraft Forge modloader.
http://files.minecraftforge.net/ Choose the
installer, under recommended 1.6.2
Should look like this...
Recommended-1.6.2 9.10.0.784 1.6.2 07/09/2013 05:50:53 AM (src) * (universal) * (
installer) * (javadoc) * (changelog)
2. After you download the installer, open it.
It should prompt a window that tells you click to install or something like that.
After you do this. It should give you a successfully installed message.
3. Open your minecraft launcher.
4. Under the profiles tab. Select Forge and run minecraft once.
5. Quit the minecraft and quit the launcher.
6. Open your minecraft using the %appdata% thing or in your library on Mac.
7. You should see a mods.
Note: This did not appear for me until a ran minecraft once under the Forge profile (step 4)
8. Drag your desired mod folder into the "mods" folder, in your minecraft folder.
9. Open launcher again. Make sure you have your Forge profile selected.
10. Click play.
Hope this helped. Let me know in game or here if you have any problems and I can try to help.