Plumbing 101

I'd show you pictures, but it's a little gross...not real gross, but ya know when you can't get to something to clean, but the dirt and grime can get there to mess up? It's that kind of gross.
Anyway...
I got up this morning all fired up and rarin' to go. Got my coffee, sat at the computer and then started dreading tearing apart the toilet. I mean really, I have to tear the toilet apart! The tank thing on top has to come off in order to fix the flush valve, which is what has been keeping me awake nights. Weeeee ch, ch, ch, ch Weeeeeee
I finally relented and got dressed. Then swore a little cause I really, really did not want to go out and shut off the water to the house. I don't know why that bugs me, but I hate having to shut the water off. And then I couldn't shut it off. The valve at the house doesn't work anymore. So I went out to the meter to shut it off and the shut off valve is covered in about six inches of dirt! (How do they read the meter then?) I called the water company to ask them just that and she told me I wasn't supposed to shut the water off at the meter by myself, because if I damaged it, I would be responsible. How a simple thing like that would make me responsible after all these years I will never know. Oh and then she told me they have some magic wand thing that reads the meter. No more pulling off the cover and actrually looking at the numbers. (I'm surprised it doesn't just go on their computers and then lick the envelope to send the bill in the mail for them)
She sent a man over to shut the water off at the meter and I got the usual lecture about doing it myself. I told him to marry me and then I would be able to afford to hire a real plumber to come and do this all for me. I'm capable even if I am JUST a woman! Excuse me, but I have the tool to shut the water off, and all the man did was get out his tool that looked just like mine and turned the little knob thingy just like I would have done. Hmmm. Wow, I can't believe that people have to go to college or trade school to learn that stuff.
So, water off, toilet tank drained. I start to pull of the angle stop to replace. It is the reason I couldn't just shut the water off at the toilet, it's old. When I took it off, I panicked because the pipe it is attached to is looking like it came from Roman times. Old, rusty and in need of replacement which would require a real plumber, and apparently I am allergic to real plumbers.
I said a little prayer, bit the bullet and ran down to my local hardware store, where I used to work several years ago and where I haven't stepped foot since the ass laid me off. But I had to go there, because even though the water was shut off there was still a tickle coming in and I had no time to waste.
Got the new angle stop and a new supply line and asked the owner who is also known as the ass, if there is a possibilty of fixing the now rusted out 1/2" galvanized pipe coming out of my wall if there is a tiny bit of thread left on it. He assured me it could be salvaged if I just bought a $15 tool. "Sell it to me!" Shit, I'm bleeding money here!
Came home, put on my contortionist costume and proceeded to finish what I started. The angle stop did go on as promised! YAY! I now have a shut off to my toilet once again...Did I say YAY! yet? I unscrewed the first set of nuts that hold the toilet tank on to the bowl, and got the tank off. Herein lies the mess. Things were disintrigating back there. Nothing that can't be replaced...which is why I am doing this. The disintrgation is what has been causing the toilet to sing.
Now I am at a spot where I needed a little help from my favorite can of WD40. The second set of nuts don't want to come off easily, so I am soaking them for a while.
Be prepared for Plumbing 102 in the near future. Take notes, there will be a quiz later.