Lautering

So I may be stupid but I am getting confused when it comes to lautering.
First lets assume I want to brew a five gallon batch of beer and I want to use an igloo style water cooler for mashing /lautering. Do I then need a 7 gallon cooler?
Second do I only use the first few quarts of run off for recirculation and then add new water to finish lautering?
That is where I a, getting lost because I am reading to use 1.5 times as water to lauter as I used to mash but wouldnt that give me 12 gallons. So should I be mashing with less or lautering with less? Like I said I may be stupid but I am definitely confused.

http://hbd.org/cascade/dennybrew/ is a good piece for the beginning all-grain brewer. So is this http://www.suebob.com/index.php?option=com_content&view=section&layout=blog&id=7&Itemid=62 there is an all-grain primer here

Good luck!

This post tells you everything you need to know about how big you should make your mash/lauter tun:

https://www.homebrewtalk.com/f11/how-big-your-mash-tun-needs-123585/

Second, yes, recirculating (vorlauf) is usually done a few quarts at a time until there are not a lot of grain particles coming out in your wort. Once you aren't getting particles, you can just run off the wort into your kettle.

As for your question about lautering, I believe you're actually asking about sparging. Sparging is when you add new water to "rinse" the grain of all available sugar - lautering is actually the entire process of draining wort (which includes recirculating/vorlauf, runoff, and sparging).

As for how much you should be sparging with, I'm still new to all grain brewing so I use calculators. There are a number of great tools online that will calculate how much volume of water to mash with and how much volume to sparge with. There are lots of newbie-friendly recipes out there that will do the same thing, but remember that YMMV depending on your equipment.

Good luck and have fun!

Thanks those helped a tun ha. So yeah I had my terminology mixed, I said I was stupid.