YOU MUST HAVE A DECENT COMPUTER!
1.7.2 ONLY. BACKUP ALL YOUR SAVES!
To first begin the installation, its best to create a fresh install, make sure to backup any Saves or texturepacks you want. Once you do a fresh install, run minecraft 1.7.2 once.
Then you need to download Minecraft Forge installer for 1.7.2. (Get version 10.12.0.997). Once downloaded, run it.
After forge is installed, run minecraft to make sure it is working properly.
Now go to your .minecraft folder. (Use Windows Key+R and type %appdata%). Make a mods folder and a shader packs folder.
After you make the folders, you need to download the Shader's Mod Core. Once downloaded drag and drop into the mods folder.
Now time to get some Shaders!
I recommend Rudoplays as it is nice and vibrant, SEUS is also nice, but it is dark, Lights do give of a glow that is really nice. Mr.meeps feels more real.
After you download your favorite shader. Drag n drop into the shaderpacks folder.
And you're almost done! Start minecraft again with the Forge profile.
FOR PEOPLE USING RUDOPLAYS AND GET RIPPLES IN THE WATER
You need to download 1.7.2 Optifine and drag it into the mods folder.
If you need any help, add me on steam.