Detailed description on how to install minecraft mods?

Well depends forge or non forge, i would personally recommend forge since its easier to install, also as a side note this works for windows only, mac or anything apple related works differently

forge:
1. Look up forge on google and click on the first link (should take you to the forge website)
2. There you should see all the forge versions, pick your desired version (i recommend 1.6.4 because it has all the good mods that haven't updated like morph mod and orespawn) right next to the version there should be a bunch of things go to where it says download below it there are also a bunch more things click on installer
3. It should have downloaded and once its done downloading a little menu should come up just hit ok and it should automatically install to your minecraft DON'T TOUCH ANYTHING ELSE OR IT MIGHT NOT INSTALL TO THE RIGHT FILE
4. Now that forge is installed hit the windows button on your keyboard or open it manually on you computer, then type in %appdata% and hit enter
5. This should take you to your roaming folder and on the very top you should see a.minecraft folder open it
6. In the.minecraft folder you should see a mods folder if there's not one there then you didn't install forge correctly
7. If you want to install a mod all you have to download the desired mod HAS TO BE FOR MINECRAFT 1.6.4 AND HAS TO BE FORGE OR IT WON'T WORK then you just move the mod file into the mod folder that i told you about and it should work

a couple more things in order for forge to work you have to play through minecraft 1.6.4 first without selecting forge profile or it won't work and in order to play with mods got to the minecraft launcher and select profiles in the bottom left corner and choose the profile called forge select it and you should be good

non-forge mods: i'm just going to link you to a video because to type this would take me about another hour and a half so here it is

i know the title says 1.7.9 tested but it works for 1.6.4+ also i recommend forge mods because easier to install and most of the cooler and better mods are for forge