My 2 cents? Start buy buying this book: http://www.walmart.com/ip/2191155?ad...l5=pla&veh=sem
Most people here will agree it is a great read. It was my number one resource during my extract years and its a fun read to boot.
Second, if you are unsure of how big of a pot you need and money is an issue, then go with (man I hope I don't get torched for this) a 10 gal aluminum. I got mine for ~$50 and was able to add valves and a boil screen easily (I am in no way handy, so this is a testament to how easy it is).
I learned two things quickly, I love making beer, and because of that, I wanted to go all grain. well guess what- I was only a cheap rubbermaid setup from that. Now that I have traded in my monopoly money lifelstyle for a real one, I was able to manage a [modest] kettle upgrade to on 15 gal ss pot (I am using another 8 gal SS pot that was a gift from my parents with plans to upgrade soon.) But the first 5 years of brewing, both extract and AG, were done with super cost-efficient aluminum.
My point is, while I would love 3 20 gal blichmanns, I feel the money can be better used elsewhere because a 15 gal SS concord pot with self installed weldless fittings, works shockingly well
set your budget, plan for 3-5 years from now and make your plans accordingly. If you can afford a big SS guy now, I'd go for it, but I know that lots of us can't/couldn't. Best of luck to you sir, and welcome to the addiction.