Originally Posted by polymorphself

My honest opinion from someone who was in your shoes just several years ago: Just take the damn bike apart.

Seriously. It doesn't sound like you need to be riding it right now, and as long as you are riding it right now you will never fully enjoy it because all of the above thoughts will be circulating in your head.

Step 1: Buy a bike stand. You really don't want to start without this. I did my first bike this way and it took me twice as long as it should have.
Step 2: Start disassembling the bike. A basic toolset will get you through much of this aside from the cranks/bottom bracket and freewheel. Thoroughly photograph every single component you take off from several angles before removing it.
Step 3: As you take parts off, if they are rusty have a box/bucket/Tupperware/whatever full of EvapoRust (most hardware stores) to dump it in. Whatever looks good dump into a big ziplock bag, keeping like parts together (all brake stuff in one bag, all headset stuff in another etc). Dump what looks like it can't be used into another bin. You'll likely want to toss out and replace the chain and brake/derailleur cables, however, keep them until you have the new ones to make it easier to know what length to cut the new ones. As you get to components you don't have tools for: go buy them.
Step 4: Clean the frame and fork. Use warm soapy water and wash it down/clean it out. After this I always then use a polish followed by a wax. Is this necessary yet? No but seeing how great the frame can look after this can be inspirational.
Step 5: Clean every component thoroughly (do searches here to see which cleaning materials work best with which components).
Step 6: Sort out what you will need for the bike and put it on order.
Step 7: Start re-assembling. For the most part this will be as easy as assembly was, short of the bottom bracket, brakes and derailleur. Googling any of these and bikes forums C&V will find you a great thread on how to do it. Short of that you can youtube RJ the Bike Guy and whatever component you're trying to assemble. Worst case, get everything back together short of the trickier parts and THEN drop it at your LBS and just ask them to install the rest. Make sure to re-grease the bottom bracket and headset, as well as the wheel hubs (maybe have your LBS do the hubs when you're done). Also, dab a little grease on anything threaded as your'e putting it back on.
Step 8: Give it one more quick clean and off you go!

Also, start a thread for it here when you begin to keep all of your progress and advice in one place.