big tune-up...first time...please help!

Hey Guys. I’m just about to roll 125k miles and thought I’d do a major tune-up…only thing is I don’t know how to do half this I plan to do. I was just wondering if the price of the parts I’m changing sound right…and if someone would explain, step by step, how to clean/replace the parts. Here’s my to-do list-Change and replace Spark plugs ($8 a piece) how do I get to the spark plugs and how do I get them out? I’m using ACdelco double platinum, is that okay to use? (I really need step-by-step directions!) and what do i set the gap to?-Cleaning throttle body while its off, any steps on that?-Air Filter ($20 at the most)-Fuel Filter ($30 at the most) I know where it is, but how do I get it out and change it? (I really need step-by-step directions for this one too!)-Transmission Filter I’ve been noticing hard shifts lately, and I had a flush on it 5k miles ago. I’m not going to be the one doing this. So I’m going to have a shop do it for me…anybody know how much that’ll cost?-Oxygen Sensor I see one on the passenger side before the cat. Is that the only sensor, or is there more? I can do this myself, all I do is disconnect battery, use wrench to remove, replace, and tighten with anti-sieze, right? And they run about $60 a piece, am I right?But before I do all that, I’m also planning on hosing down the engine. I know what to do, but someone recommended that I cover the electrical components so water doesn’t go in. what is/are these electrical components? Because I thought it was just the alternator..Sorry for all the question, just nervous…car has a lot of miles and I want to keep it for ever! Do you guys think that there’s other things I can do? Thanks!

well, since i can't get help from my other questions...i just wanted to let you guys know that i will be changing my fuel filter and air filter today. I'm choosing to go with fram for both filters. I just wanted to know if they are reliable, because i've heard some negative things about their oil filters. any opinion on frams? if they arent a good brand, then what is?

I'd stay with a GM or Purloator Pure one filter. I would walk you thru the required info but the amt. of typing and step by step info is prohibitive for me, if you get stuck somewhere post back, remove the plugs on a cold engine only, remove the upper air intake system to access the coils, remove the coils over the plugs to access. I'd avoid hosing the engine. You will need to depress the clips on one side of the FF, there is a pressure relief valve in the line near it. Plug gap is .050.