Need an Education

I've been lurking these message boards for awhile and have finally decided to start posting. I need an education yeast. I'm about to brew a DFH 60 Clone, and a 90 Min Clone. I've read all sorts of stuff about yeast starters and double pitching. Some of the things I've read recommend pitching a ton of yeast for higher gravity beer, ex. the 90 Min, but how much is "more?" So far I've only brewed with kits, but my next endeavor will be my recipe. My limited knowledge makes me just want to buy one "packet" of yeast and go with it, but I know there has to be more to it than that. I joined these forums to learn, as brewing has became a hobby of mine and will be going forward. I'm now preparing for a knowledge shower...

see this thread

it is full of useful stuff, like this picture... and more!

Get liquid yeast and make a starter in a sanitized 1 gallon jar or 2L soda bottle:
-Fill it with a boiled and cooled down mixture of 150g DME and 40oz (1.2L) water
-When it is room temp, add the yeast that you have previously smacked and sat down on the counter to warm up to room temp as well.
-Leave the lid on the bootle loose or place foil over the hole and sit the bottle on a dark shelf at room temp.
-Agitate the bottle to stir everything up as often as you can (hourly is best).
-After 40 hours, place in fridge for 12 hours.
-Dispose of the clear liquid on top of the yeast cake.
-Sit the bottle on the counter and warm to room temp.
-Agitate and pitch the bottle in the fermenter. Rinse any solids left inside with bottled water.

After you understand that, go here to get more accurate with the cell count.
http://www.yeastcalc.com/